Problems burning Kickstart

[Computolio]

I've been trying to burn Kickstart 3.1 ROMs for my 1200. I took a (40.68) Kickstart 3.1 image, split it into even and odd words using WinHex, and burned the resulting two files to two 27C2048 EPROMs. I put them in the kickstart sockets and I get a blank screen when I turn the machine on. I've swapped the ROMs around and have always made sure to put them in the exact same way.

There's something I'm missing here, and I don't know what. The mask ROMs still work fine, and I'm guessing this is one of those cases where the mask ROMs have a slightly different pinout than the equivalent EPROMs.

Has anyone else tried this before?

[Jope]

The 27C2048 doesn't strike me as being the correct model to be directly plugged into the A1200 motherboard.

I seem to remember that the 256kB chip is the 27C200 and the 512kB chip is 27C400.. So you'll need a pair of 27C200s. Also perhaps a 23C2100 can be used as the 256kB chip and a 23C4100 as the 512kB chip..

http://www.rabayjr.com/Download/MXIC%2023c2100.pdf

It's becoming increasingly hard to locate these chips, I'd suggest you use a modern flash part and create a personality module to plug it into the Amiga.

[whiteb]

I can confirm, i have a KS2.04 for A500 on an MX23C4100-1001 (512K).

[alexh]

The amiga EPROMS have a different pinout to regular EPROMS. You do need 27c400's or clones.

Get 27C400's as they work fine in A1200's (half empty) and A500's.

You can get them 2nd hand from Europe for about €10 each

[DoctorQ]

Brilliant to pay €10 for each rom instead of paying 18 EURO for a legal set of roms....

[alexh]

Or buy them from America for $5 each including delivery?

[Computolio]

The EPROMs were free, pulled out of some broken-down UNIX terminal and erased. I should have caught the difference in pinout, that was really dumb of me. I'm really lucky I didn't fry anything.

Anyway, this is more a fun experiment than anything else.

[Computolio]

Seeing as how 27C200s are hard to find at the moment, would there be any problems in using 27c400s instead? What would the unused half of each ROM be filled with, and wouldn't they conflict with the Slow RAM address space?

[Jope]

Just burn it another time to the top of the chip if unsure. Otherwise tie the highest address line to ground with a jumper wire.

The chip won't magically overwrite your slow ram, as the machine will only address 512kB or ROM.. If the surplus address line is left hanging, there's no telling what the chip will give out at any given time (thus burn the image two times to fill the high half of the chip if you don't plan on making sure that the address line doesn't float).

[amethyst]

Computolio, what are you are using to burn your eprom?
Do you think something like this is suitable for the task?
http://cgi.ebay.co.uk/16bit-40-42pin...QQcmdZViewItem

I've seen lots of willem programmers on ebay and wondered if they can be used to burn kickstart roms.

[amethyst]

Answering my own question here, I think the willem eprom programmer is suitable for burning kickstart roms based on the info I found here:

Original kickstart rom device specifications:
A500, A1200 (MX23C2100)
A500+, A600 (MX23C4100)

Suitability of using Willem Programmer to burn kickstart roms:
http://www.willem.org/cgi-bin/yabb2/...1100593393/7#7
http://www.willem.org/cgi-bin/yabb2/...1120237226/0#0

Perhaps, the sockets on the 40/42 adapter should be replaced with ZIF sockets though.

[alexh]

I think you may require a converter board for the unusual pinout of the 27c400 chips. Make doubly sure as converter boards can cost more than EPROM programmers.

[amethyst]

Originally Posted by alexh

I think you may require a converter board for the unusual pinout of the 27c400 chips. Make doubly sure as converter boards can cost more than EPROM programmers.

The converter board (are you referring to the 40/42 pin adapter board) comes with it I believe. Here's the picture of it. This is a description from the sellers website. It supports these devices: 27C1024 (27C210), 27C2048 (27C2002), 27C4096, (27C4002),M27C400(DIP40), 27C800, 27C160, 27C322. You put the 27C400 eeprom in the 42 pin socket but start at pin 2 of the socket.

UPDATE:
Having investigated a bit further on some forums, I've changed my opinion of the Willem eprom programmer.
In particular the version of eprom programmer that is only powered through the USB port.
It seems to have problems providing the required voltage during the eprom programming stage, ie. Vcc should be around 6V but due to the flawed design it only provides about 5V. So I think this particular eprom programmer is one to avoid.

UPDATE #2:
I bought one anyway and it works

[amethyst]

For the A500, A1200: Comparing the pinouts of the MX23C2100 and the 27C400 from their datasheets. Pin 1 is the only difference between the two. MX23C2100 has this as a no-connection pin and the 27C400 has this pin as Address input A17. This must be what jope is talking about here:

Originally Posted by Jope

Just burn it another time to the top of the chip if unsure. Otherwise tie the highest address line to ground with a jumper wire.

The chip won't magically overwrite your slow ram, as the machine will only address 512kB or ROM.. If the surplus address line is left hanging, there's no telling what the chip will give out at any given time (thus burn the image two times to fill the high half of the chip if you don't plan on making sure that the address line doesn't float).

However, for the A600 and A500+, the 27C400 is identical pin-for-pin to the MX23C4100

[amethyst]

I bit the bullet and bought the Enhanced Willem Programmer (regardless of what I had read about them) and this particular programmer worked fine for me when burning kickstart roms using 27C400 eproms. I tested an eprom in my A500, A500+, and A600 and they all worked fine. I haven't tested one in my A1200 yet as it requires 2 eproms. Will test this soon as well.

Useful note: If you read a kickstart rom chip into the eprom programmer and want to use it in winuae you have to perform a "swap BYTE" operation and then save the file.

This eprom programmer will also come in handy for programming eproms for my C128 and Plus/4

PS. If you do have a choice between a USB only powered willem programmer and one with selectable power options i.e dual power, choose the dual power one.

[amethyst]

In answer to the Computolio's original question, here's how to burn a kickstart eprom set for an amiga a1200 in 4 easy steps:

Requirements

• Eprom Programmer (with support for 27C400)
• WinHex utility (registered version) or write your own code to perform Steps 1 to 2.
• Kickstart rom file being used in WinUAE (not encypted and legally created from your own set of A1200 kickstart roms, of course)
• Two blank 27C400 eproms

Step 1: Split the kickstart rom file
In WinHex select: Tools -> FileTools -> Dissect -> Wordwise (16-bit)
Select source kickstart rom file
Type in destination filename#1 eg. U6A_tmp.rom (00000-3FFFF for U6A)
Type in destination filename#2 eg. U6B_tmp.rom (00000-3FFFF for U6B)
Now you have two smaller rom files

Step 2: Fill addressable unused memory space for both eproms
Now, we're going to copy the contents of addresses 00000-3FFFF to 40000-7FFFF for U6A_tmp.rom
To do this, in WinHex select: Tools -> FileTools -> Concatenate
Type in destination file for a blank rom file to be created (eg. U6A.rom)
Append file U6A_tmp.rom to U6A.rom
Repeat this again, append source file U6A_tmp.rom to U6A.rom
Select Done and a message box will appear: 524288 bytes from 2 files were concatenated to "U6A.rom"

Repeat Step 2 using U6B_tmp.rom to create U6B.rom

Step 3: Burn the kickstart eproms
Start up eprom programmer software with 27C400 device selected.
Load U6A.rom to the buffer
Perform a swap BYTE operation on the buffer contents
Insert a 27C400 eprom into the eprom programmer and burn buffer to the eprom.
Apply opaque sticky label over the eprom window and mark it "U6A"

Repeat Step 3 for U6B.rom, marking it "U6B"


Step 4: Install eproms into A1200
Insert eprom U6A into U6A socket and eprom U6B into U6B socket (make sure the eprom has correct pin connections and orientation).
Power up and hey presto it works!

For more details on opening up your amiga and installing the eproms read the amiga kickstart guide from aminet.

[amethyst]

Here's how to burn a kickstart eprom in 2 easy steps

Requirements

• Eprom Programmer (with support for 27C400)
• Kickstart rom file being used in WinUAE (not encypted and legally created from your own set of A500, A500+ or A600 kickstart roms, of course)
• One blank 27C400 eprom

Step 1: Burn the kickstart eprom
Start up eprom programmer software with 27C400 device selected
Load the kickstart rom file to the buffer
Perform a swap BYTE operation on the buffer contents
Insert the 27C400 eprom into the eprom programmer and burn buffer to the eprom.
Apply opaque sticky label over the eprom window and mark it with version

Step 2: Install into Amiga
Insert eprom into socket (make sure the eprom has correct pin connections and orientation).
Power up and voila it works!

For more details on opening up your amiga and installing the eproms read the amiga kickstart guide from aminet.

[gizmomelb]

thanks amethyst - extremely userful info!

any hints/tutorials on burning a ROM for an Amiga 3000 please?

[amethyst]

Originally Posted by gizmomelb

thanks amethyst - extremely userful info!

any hints/tutorials on burning a ROM for an Amiga 3000 please?

Here it gives the following info
for the A3000: U180 (D0..D15), U181 (D16..D31)
for the A1200: U6B (D0..D15), U6A (D16..D31)

So I assume that the A3000 must have two 16-bit rom sockets: U180 and U181, like the A1200. Not having an A3000 to test, my guess is that you would peform the same steps for burning a kickstart eprom for the A1200 except that the eprom for U6A would be U181 and the eprom for U6B would be U180.

[gizmomelb]

thanks amethyst!

[amethyst]

Originally Posted by gizmomelb

thanks amethyst!

No problem!

[lopos2000]

Exellent info. Thanks amethyst.

[MrZammler]

While on the subject, does anyone know what eproms are suitable for burning the extended roms on the CDTV 2.30?

[amethyst]

Originally Posted by MrZammler

While on the subject, does anyone know what eproms are suitable for burning the extended roms on the CDTV 2.30?

27C400 eprom is suitable for the CDTV kickstart rom (MX23C2100 part no. 315093-02) in socket U13. According to the original kickstart info I found from here and if you check the parts list and rom schematics for the CDTV here

[amethyst]

Originally Posted by MrZammler

While on the subject, does anyone know what eproms are suitable for burning the extended roms on the CDTV 2.30?

Correction:
If you were referring to the two CDROM Driver EPROMs (in sockets U34 and U35) on the CDTV then they use 27C1000 EPROMs.

In the parts list (see partslist-p1.png) they are listed as:
252606-01 ROM CDROM DRIVER, ODD U35
252607-01 ROM CDROM DRIVER, EVEN U34

In the schematic (see schematics-p7-dmac-scsi.png) the parts are shown as 27C1000 EPROMs.

If you check the datasheet, it's probably also possible to use a 27C1001 but you would have to make an adapter to swap pins 2 and pins 24 (or bend these pins up and connect wires to socket) as these are the only pins that differ:

            27C1000     27C1001            
pin 2        A16            ¬OE
pin 24       ¬OE           A16

[kas1e]

amethyst
what do you said in 'Here's how to burn a kickstart eprom in 2 easy steps' only about one blank eprom ? need only one ? one socket will empty ?

[amethyst]

Originally Posted by kas1e

amethyst
what do you said in 'Here's how to burn a kickstart eprom in 2 easy steps' only about one blank eprom ? need only one ? one socket will empty ?

Check the other guide posted before it. There are 2 guides posted, one for the A500, A500+, A600 (1 rom socket) and the other one is for the A1200 (2 rom sockets).

[kas1e]

ah yes, sorry.
btw, programmator is need it , or can be possible burmimng from somethink like selfmade programmator over lpt/etc port ?

[amethyst]

Originally Posted by kas1e

ah yes, sorry.
btw, programmator is need it , or can be possible burmimng from somethink like selfmade programmator over lpt/etc port ?

As long as the eprom programmer supports a 27C400 eprom, then it should be able to burn a kickstart eprom.

[whiteb]

Slightly Digressing here....

I have 3.0 kickstart in my A1200, is it possible, once the chip is read, or using a Version 3.0 image, patch everything up (with TD64 and the slurry of other patches for fastfilesystem) and burn it back to the required EPROMS.., this way all that will be needed for 3.0 is to just load SFS yeah ?

Would this work ?

What utilities would I need to do this ?

[lopos2000]

Originally Posted by amethyst

Here's how to burn a kickstart eprom in 2 easy steps

Requirements

• Eprom Programmer (with support for 27C400)
• Kickstart rom file being used in WinUAE (not encypted and legally created from your own set of A500, A500+ or A600 kickstart roms, of course)
• One blank 27C400 eprom

Step 1: Burn the kickstart eprom
Start up eprom programmer software with 27C400 device selected
Load the kickstart rom file to the buffer
Perform a swap BYTE operation on the buffer contents
Insert the 27C400 eprom into the eprom programmer and burn buffer to the eprom.
Apply opaque sticky label over the eprom window and mark it with version

Step 2: Install into Amiga
Insert eprom into socket (make sure the eprom has correct pin connections and orientation).
Power up and voila it works!

For more details on opening up your amiga and installing the eproms read the amiga kickstart guide from aminet.

I tried it yesterday and it works a treat. Burnt a 3.1 kickstart for my Amiga 600.
Thanks amethyst

[Sandgunner]

Have exactly everything detailed in the steps.
Have a nice collection of 27C400 EPROMS that pass
blank checks and UV wipes perfectly.

Have a decent UNIMAX universal programmer
Have original kickstart 3.1 rom image from working
A2000.

Loaded of the rom image, performed byte swap
Burned chip. Passes verification.

Plug chip into A500 boot..........
Power light flashes then system fault press left mouse button.
I've tried on 7 chips. All no go when put into a rev 6A A500,
This is the same unit as the A500+ just minus the extra 512k chip
and clock but the MB has the silkscreen for where they would go.

Am I missing something in the translation?
I know the 27C400 is the correct part, matches exactly to the
MX part used for almost every 3.1 kickstart out there.

Anyone else use a UNIMAX or MULTIMAX programmer have an idea
where I might be going wrong?

I'm doing this for fun and education. I own every Amiga production
model made and am using my off time now to have fun and tweak the
kickstart with patches.

Angelo

[lopos2000]

Have you tried to read the programmed EPROM to check if they have any data on them?
I'm using the USB Enhanced Willem Programmer with an 16bit adapter and it works fine.

[amethyst]

Originally Posted by Sandgunner

Have original kickstart 3.1 rom image from working
A2000. Loaded of the rom image, performed byte swap
Burned chip. Passes verification.

Was the saved original ROM image tested in WinUAE?

Originally Posted by Sandgunner

Plug chip into A500 boot..........
Power light flashes then system fault press left mouse button.
I've tried on 7 chips. All no go when put into a rev 6A A500,
This is the same unit as the A500+ just minus the extra 512k chip
and clock but the MB has the silkscreen for where they would go.

Am I missing something in the translation?
I know the 27C400 is the correct part, matches exactly to the
MX part used for almost every 3.1 kickstart out there.

Anyone else use a UNIMAX or MULTIMAX programmer have an idea
where I might be going wrong?

I'm doing this for fun and education. I own every Amiga production
model made and am using my off time now to have fun and tweak the
kickstart with patches.

Angelo

Did you also read the Amiga Kickstart guide? There are different revisions of the A500 PCB, maybe that's your problem, from the Amiga Kickstart Guide:

1. Place the A500 unit upside down on a flat surface.
2. Use a #10 Torx driver to remove the six (6) case screws.
3. Turn the unit right side up. Remove the top cover by grasping at the rear
corners and lifting up.
4. Note the orientation of the keyboard wires, then remove the keyboard assembly
by grasping the keyboard cable harness and gently pulling straight up. If there
is a ground strap attached to the keyboard, detach it. Set the keyboard
assembly aside.
5. Use needlenose pliers or a similar tool to straighten the four tabs which
secure the top shield. Remove two (2) screws at the front of the PCB and two (2)
on the left side of the PCB. Now remove top shield by lifting straight up.
Set the shield aside.
6. The main printed circuit board is now in full view, except for the portion
covered by the floppy disk drive. The operating system ROM IC is located at
position U6, just to the right of the 68000 CPU chip.
The old ROM chip should be marked 315093-01, -02 or, if your system is already
upgraded, V2.04 (37.175).
7. Note the orientation of the old operating system ROM, then remove it from the
socket.
8. IMPORTANT: There are several different versions of the A500 PCB: Rev 3, Rev 5,
Rev 6A and Rev 7
(The revision number is printed on the top of the main board in the front right
corner). Installation differs depending on the PCB revision:
1> For Rev 3 and Rev 5 boards, the ROM socket must have pin 1 connected to pin 31
and the ROM IC must have connected pin 21 to bent-up pin 31.
2> For Rev 6A and above, the ROM must not have any connection.
9. Align the 3.1 ROM with socket U6, and press firmly into place. Be cautious
not to bend pins.
ROM installation is now complete. It is advisable to re-assemble the keyboard
and test the system prior to fully re-assembling the shield and top case.

Does that help?

[alexh]

For Rev 3 and Rev 5 boards, the ROM socket must have pin 1 connected to pin 31 and the ROM IC must have connected pin 21 to bent-up pin 31.

This makes sense if you look at the pinout of the EPROM. On the Rev3/5 boards (which only came with 256Kbyte Kickstarts) they didnt wire Address 17 to pin 1. But fortunately they did wire it to the "never used" pin 31 (Byte).

Plug chip into A500 boot..........
Power light flashes then system fault press left mouse button.

The above fix is DEFINATELY what you are missing. These results confirm it. They mean at least some of ROM is correct and working as the "Press Left Mouse button" screen is not a hardware feature but software and part of the KS ROM. Without Address17 connected to pin 1, the amiga can only access the lower 256Kbyte of the ROM.

[Jope]

Just to add my extreme opinions to the discussion..

When I installed my first 2.04 rom into the rev 5 A500 I had, I only jumpered 1 and 31 and plugged the chip in, didn't bend anything up.

[Sandgunner]

Originally Posted by alexh

This makes sense if you look at the pinout of the EPROM. On the Rev3/5 boards (which only came with 256Kbyte Kickstarts) they didnt wire Address 17 to pin 1. But fortunately they did wire it to the "never used" pin 31 (Byte).


The above fix is DEFINATELY what you are missing. These results confirm it. They mean at least some of ROM is correct and working as the "Press Left Mouse button" screen is not a hardware feature but software and part of the KS ROM. Without Address17 connected to pin 1, the amiga can only access the lower 256Kbyte of the ROM.

Only problem is that I have a revision 6A A500 motherboard.
According to what you posted the 6A is not supposed to have anything jumpered/crossed etc. which matches the handout that comes with the original 3.1 kickstart rom chip upgrade.

However it does make sense that the burned rom is not being addressed properly in the upper area. I'll try the socket and chip jumper and see what happen. More oddities with the chips though.
The original 3.1 kickstart upgrade is a macronix 27C4100 and the EPROMS
I am using are AMD 27C400 which are identical pin for pin.
The oddity is that these devices show as size 40000h (262144) X 16bit
yet the file obtained from the 3.1 original kickstart is 512k???

A little confused on the "burn it a second time" item. In my testing I don't
think it's an addressing error but an incomplete binary image fault.
What baffles me though is that the proper Kickstart 3.1 EPROM purchased
is identical in every specification as the AM27C400 EPROMS I am using
to proof burn a 3.1 kickstart.

I have read directly from the original 3.1 kickstart rom and wrote this
directly with verify into my AM27C400 EPROMS.
Still no go and getting the errors I detailed earlier.

[Sandgunner]

ok for the gurus out there.

IS the AMD 27C400 a 512k part or a 256k part?

Now the fun part before you answer the above.
The identical spec part for Macronix is the
MX27C4100
Which is identical in all spec respects to the AMD 27C400.

Now the problem that has me stumped.
I have a purchased kickstart 3.1 chip for the A500-A2000
this IS a Macronix MX27C4100 part.

On the EPROM programmer list BOTH parts show as 256K.

How in the hell did they burn a 512k binary image (kickstart 3.1)
into a MX27C4100 which is by the manufacturers spec sheet
and the EPROM programmer, a 256k part just as the AM27C400
EPROM is???????

Ok gurus out there. Have at it

[Jope]

Those eproms have both a byte mode and a word mode.

The smaller 27c2100 part is 256kbitx8 or 128kbitx16..
The larger part is then 512kbitx8 and 256kbitx16.

However both values for each chip naturally come to the same amount in kiloBytes.. It's just the layout of the chip that's different depending on which mode the chip is read in. The Amiga uses the word mode (16bit).

And how to convert.. We start off with the smaller 27c2100 part that should fit a 256kB kickstart image. Remember, that there are 8 bits in a Byte and ROM / RAM chip sizes are reported in bits.

Thus 256kbitx8 is: 256kilobits times 8 (now we have the amount of bits the chip contains without any layout info) divided by 8 to get bytes. So 256kB.
If we look at the chip in word mode, we have 128kilobits times 16 divided by 8.. What's the value in kilobytes?

The explanation above is not 100% thorough, as I'm again feeling very lazy.. But at least you can get a rough idea what it's about.. If you have a 256kx4 part, then it's (256 * 4)/ 8 to get the amount of bytes it stores.

It is important to remember that bits are b and bytes are B. I always cringe when I see people talking about the new "160gb" drive they bought..

[Sandgunner]

[quote=Jope]Those eproms have both a byte mode and a word mode.

The explanation above is not 100% thorough, as I'm again feeling very lazy.. But at least you can get a rough idea what it's about.. If you have a 256kx4 part, then it's (256 * 4)/ 8 to get the amount of bytes it stores.

Thank you for the EPROM 101. It's been a looooong time heehee

Here is where I am at. The chips are indeed 512K
40000h X 16bit

Now here is where I'm going nuts.
Inserted a working 2.04 kickstart rom in the programmer (this is not
an elcheapo unit) select the exact device type in the dropdown
menus. In this case the 2.04 kickstart is a Macronix 27C4100
Read the contents into the buffer.
Remove the 2.04 kickstart, insert AMD 27C400 (identical layout
part pin for pin and capacity)
Burn binary image to EPROM exactly as read from the source so no
byte swapping is required here as this is not a UAE or other image I'm
working with.

Take newly burned EPROM to my testbed, an A500 with a revision 6A
motherboard. This revision requires no jumpers or patches whatsoever
to work with these EPROMS.

Fire her up. I'm now getting the Kickstart insert screen. GREAT...almost
loading workbench or a self booting floppy like Lemmings causes a system
crash, flashing power light and reboot.

Comparison details. I take the supposedly bad EPROM that is crashing
back to the programmer and read it's contents saving it to a binary
file. I then re-insert the original working 2.04 kickstart and read its contents saving to a binary file.
I do a file comparison on the two. They are identical!

WTF?

Do note that during the burning process the buffer contents, original kickstart read and the new EPROM programming pass all verification checksums.

Here are my options in the programmer that "might" have something to
do with the failures at the device level when read in the actual Amiga.
The programmer has config options to do the following.
Gang split mode has the following config options
Byte, Even, Odd, Word0, Word1, Word2, Word3

I have used the Byte option and I get parlaysed A500 that
can boot directly from floppy but crashes without a floppy and
you can not actually run anything without crashing.

When burning I have the default buffer value set to FF as this
is its default state anyway.
In the buffer edit options I have the buffer set up as
8bit byte (hex), I also tried 16 bit word but this causes
only half the binary file to be written.

Anyone have any thoughts on what I'm doing wrong?
Key points. A500 rev 6A motherboard (no jumpers/wires required)
EPROMS used: AM27C400 256kb X 16
binary image used : taken from actual working 2.04 kickstart rom
read/write and verify all pass and match the checksums.
Read from burned roms matches identicaly to the original roms.
YES the orginal rom works perfectly in the A500.

I'm off to UV the eight EPROMS I have once again and try some
more experiments. That or go bald figuring this out.

Anyone here successfully burned a single chip kickstart for
an A500-A2000? If so what exactly was your option
setup for your programmer.

I greatly appreciate the help.