A1000 mod for permanent kickstart

Jope · 02 December 2007, 19:10

Intriguing.. Two jump wires, two sockets and four eproms later you too can have an A1000 with permanent kickstart. 256kB kickstarts only without additional address decoding.

http://www.amiga.org/modules/newbb/v...=41859&forum=8

TjLaZer · 15 August 2018, 05:23

Anyone have the info on Amiga.org? It's down

FOL · 15 August 2018, 09:40

Quote:

Originally Posted by TjLaZer

Anyone have the info on Amiga.org? It's down

It wouldn't help, as that link is from the xoops AO days. Link was broke when AO changed to VB. I have just checked and am unable to find that topic under the id listed in link. I will see if I can find topic in question.

xArtx · 16 August 2018, 22:17

Why not use a real Kickstart (or at least single EEPROM) ?
[ Show youtube player ]

8 Bit Dreams · 16 August 2018, 23:07

https://www.amigalove.com/viewtopic.php?f=6&t=540
Don't want to wait? Grab a ready built one from here:
http://www.amibay.com/showthread.php...CPU-relocators

Jope · 17 August 2018, 07:57

That's not the same modification though. The one linked to used the ROM sockets on the motherboard and reconfigured some jumper pads to enable the second pair of previously unused sockets.

xArtx · 17 August 2018, 15:27

Does that mean you burn 4 new 64kb EEPROMs?

Jope · 17 August 2018, 16:38

Yeps, four 27512 chips would do the trick.

Judging by the schematics, at least W2 must have 2-3 cut and 1-2 connected, this connects A16 to the highest address line of the EPROMs instead of a +5V pullup.

Then this is guessing, but W4 changes the chip select of the lower bank of chips between A16 and A17.. You'd probably want to cut 1-2 and jumper 2-3 to make this A17, as A16 was just before routed to the chips with W2 and you'd actually want the chips to not disappear when you access the higher half of them.

W5 toggles whether both banks get the same chip select, or if the higher bank gets their chip select negated from the lower bank. I'd leave this one alone so that once we hit F90000/FE0000, the second bank of chips gets active.

It could be just this simple, but I admit I suck at reading PAL equations and the 68000 "A0 = LDS/UDS" thing still has me a little stumped.

Also is the original location for the bootstrap roms f80000 or fc0000? I'm guessing they're just mirrored, so a read from fc0000 still gets us kickstart data..

Someone more experienced please feel free to chime in. :-)

TjLaZer · 26 August 2018, 01:59

Yep it's one of the original ROM upgrades for the 1000. Uses 27C512 EPROMs. I have a set of the ROMs but no instructions on how to install it. Wanted to give it a try on one of my 1000s.

TjLaZer · 26 August 2018, 02:01

Looks to be the same ROMs as the CMI Kickstart Eliminator Kit!

http://www.bigbookofamigahardware.co...t.aspx?id=1842

But that kit also needs a replacement PAL chip. Good luck trying to find this chip today! I might try it out and see what happens....

nogginthenog · 26 August 2018, 11:11

These PALs can be found on eBay. Programming it might be tricky. My EPROM programmer supports almost everything, but not PALs/GALs.

graffias79 · 28 August 2018, 16:49

Ha! Amiga = Gal Pal.

02 December 2007, 19:10	#1
Jope - Join Date: Jul 2003 Location: Helsinki / Finland Age: 43 Posts: 9,861	A1000 mod for permanent kickstart Intriguing.. Two jump wires, two sockets and four eproms later you too can have an A1000 with permanent kickstart. 256kB kickstarts only without additional address decoding. http://www.amiga.org/modules/newbb/v...=41859&forum=8

17 August 2018, 16:38	#8
Jope - Join Date: Jul 2003 Location: Helsinki / Finland Age: 43 Posts: 9,861	Yeps, four 27512 chips would do the trick. Judging by the schematics, at least W2 must have 2-3 cut and 1-2 connected, this connects A16 to the highest address line of the EPROMs instead of a +5V pullup. Then this is guessing, but W4 changes the chip select of the lower bank of chips between A16 and A17.. You'd probably want to cut 1-2 and jumper 2-3 to make this A17, as A16 was just before routed to the chips with W2 and you'd actually want the chips to not disappear when you access the higher half of them. W5 toggles whether both banks get the same chip select, or if the higher bank gets their chip select negated from the lower bank. I'd leave this one alone so that once we hit F90000/FE0000, the second bank of chips gets active. It could be just this simple, but I admit I suck at reading PAL equations and the 68000 "A0 = LDS/UDS" thing still has me a little stumped. Also is the original location for the bootstrap roms f80000 or fc0000? I'm guessing they're just mirrored, so a read from fc0000 still gets us kickstart data.. Someone more experienced please feel free to chime in. :-) Last edited by Jope; 17 August 2018 at 18:17.

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15 August 2018, 05:23	#2
TjLaZer Registered User Join Date: Sep 2004 Location: Tacoma, WA USA Age: 52 Posts: 1,915	Anyone have the info on Amiga.org? It's down

16 August 2018, 22:17	#4
xArtx Registered User Join Date: Jun 2013 Location: Australia Posts: 685	Why not use a real Kickstart (or at least single EEPROM) ? [ Show youtube player ]

16 August 2018, 23:07	#5
8 Bit Dreams Retro maniac Join Date: Feb 2017 Location: near Munich / Germany Posts: 485	https://www.amigalove.com/viewtopic.php?f=6&t=540 Don't want to wait? Grab a ready built one from here: http://www.amibay.com/showthread.php...CPU-relocators

17 August 2018, 07:57	#6
Jope - Join Date: Jul 2003 Location: Helsinki / Finland Age: 43 Posts: 9,861	That's not the same modification though. The one linked to used the ROM sockets on the motherboard and reconfigured some jumper pads to enable the second pair of previously unused sockets.

17 August 2018, 15:27	#7
xArtx Registered User Join Date: Jun 2013 Location: Australia Posts: 685	Does that mean you burn 4 new 64kb EEPROMs?

26 August 2018, 01:59	#9
TjLaZer Registered User Join Date: Sep 2004 Location: Tacoma, WA USA Age: 52 Posts: 1,915	Yep it's one of the original ROM upgrades for the 1000. Uses 27C512 EPROMs. I have a set of the ROMs but no instructions on how to install it. Wanted to give it a try on one of my 1000s.

26 August 2018, 02:01	#10
TjLaZer Registered User Join Date: Sep 2004 Location: Tacoma, WA USA Age: 52 Posts: 1,915	Looks to be the same ROMs as the CMI Kickstart Eliminator Kit! http://www.bigbookofamigahardware.co...t.aspx?id=1842 But that kit also needs a replacement PAL chip. Good luck trying to find this chip today! I might try it out and see what happens....

26 August 2018, 11:11	#11
nogginthenog Amigan Join Date: Feb 2012 Location: London Posts: 1,309	These PALs can be found on eBay. Programming it might be tricky. My EPROM programmer supports almost everything, but not PALs/GALs.

28 August 2018, 16:49	#12
graffias79 Registered User Join Date: Jul 2018 Location: Madison, WI, USA Posts: 69	Ha! Amiga = Gal Pal.

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