Gvp Scsi+2

[Zetr0]

Hello there my fellow forum Chummies

A while back our good fellow forum chummy ScrappySphinx sent me a GVP SCSI+2

Now the Device I have here doens't have any memory and this is where the problem is.

Now I do believe that these are 1Mx1 18pin DIP memory modules, but I would like to confirm that.

Heres some Hardware Pr0n =)

(stock photo, thanks amiga.resource.cx)

This being the case I would need a pinout of a compatible 18pin 1Mx1 DIP as well.

So if anyone can confirm this hypothesis and or provide me with a lucious linky to a datasheet of a compatible memory componet (only really need a pinout) the I would be truly happy =)

of course if anyone has any compatible memory I would be interested too =)

thanks for reading =D

[Loedown]

If you have a look through the description of the card itself on the link you sent it says;

• memory
• sixteen DIP sockets accept up to 2 MB RAM
• accepts 256k×4 DIPs in groups of four
• DMA between drive and 16 kB onboard SRAM

I've got an old Mtec 2Mb RAM expansion for A1000 that I offered up a while ago and no one wanted, it's faulty and I have a RAM tester here that does test DIP chips....so Mr. Zetr0 we may be able to thresh out a deal?

[Zetr0]

*heheh*

I cannot believe that I missed that part of the link.... 256x4 dips... I am sure you could here the "DOH!" and customary smacking sound of my hand hitting my forehead from where you are!!!


I Have a few lost forum souls in my collection wanna trade =D

what ya got in mind my friend =)

I shall jump onto IRC =D

[Zetr0]

okay, so I managed to find a source of Intel P21010-08 chips

however I am even more confused as the intel P21010-08 thats populated in the picture is in fact a 256x1 NMOS Dymanic RAM DRAM chips, and not a 256x4 DRAM chip as the site suggest it should be.

Now I might be a little off with my calulation as the picture of 256x1 but depending on how the bank is setup I think I have manage to confuse myself.

If each chip is 256Kx1 - looking at the banks (in groups of 4 chips)

Bank 1 (256K x 4 bit) = 128KB ---------- ( 1Mx1)
Bank 2 (256K x 8 bit) = 256KB ---------- ( 1Mx2)
Bank 3 (256K x 12 bit) = 384KB --------- ( 1Mx3)
Bank 4 (256K x 16 bit) = 512KB --------- ( 1Mx4)

with 256x4 - each bank would be 1Mx4 (0.5mb) giving you 2Mx16 with 4 banks fully populated = which is 2MB ?

Bank 1 (1M x 4 bit wide ) = 0.5MB ---------- ( 256x16)
Bank 2 (1M x 8 bit wide ) = 1.0MB ---------- ( 512x16)
Bank 3 (1M x 12 bit wide) = 1.5MB ---------- ( 768x16)
Bank 4 (1M x 16 bit wide) = 2.0MB ---------- ( 1Mx16)


now the nubers are little out in my head because to use 256x1 would require the card to be able auto config its own ram and access it differently compared to 256x4 - so can anyone confirm the above rambling ?

1. Have I got my math wrong (yes it is a sunday)
2. Have amiga.resource been given the wrong info?
3. Did some one decide to put some random 256x1 intel DIP DRAM's for just the photo shoot?
4. has anyone got a picture of this card with 2MB installed?

thanks for reading =)

[Loedown]

I would be more interested in why it has 4 octal drivers instead of two, is the card 32 bit or 16 bit?

74LS245

I ran the DMS file but that gave me no documentation, I think your best bet is to find someone with a manual and check there for a definitive answer.

[Zetr0]

According to this advert from amiga-hardware.com

SCSI+2 Multi Function Board.
Technical Highlights

• High performance AUTOBOOTing SCSI controller supports upto seven SCSI devices
• Internal and external SCSI connectors.
• DMA to/from drive to onboard 16k SRAM buffer provides high performance no affected by overscan or blitter DMA
• Zero or 2MB of zero-waitstate AUTOCONFIGured FAST RAM Expansion
• Optional Removable Media Support EPROMs with auto "Diskchange" feature for Syquest and Bernoulli drives.

so I wonder if its explicitly 0MB or 2MB - if there is no in-between then whats the jumpers J1 and J2 for?

[Loedown]

J1 & J2 = 4 possible states.

Original Resources.cx says banks of 4 chips, 16 slots, 4 X 4

If it's 256 x 4, then it's a possible 1M x 4, or 512 x 8 which still doesn't make sense.

1M x 4 banks of 4 would be 1M x 16, so if it is indeed a 32 bit card, then 16 x 1M x 4 = 2Mb @ 32 bit.

[Loedown]

Originally Posted by Zetr0

okay, so I managed to find a source of Intel P21010-08 chips

however I am even more confused as the intel P21010-08 thats populated in the picture is in fact a 256x1 NMOS Dymanic RAM DRAM chips, and not a 256x4 DRAM chip as the site suggest it should be.

Now I might be a little off with my calulation as the picture of 256x1 but depending on how the bank is setup I think I have manage to confuse myself.

If each chip is 256Kx1 - looking at the banks (in groups of 4 chips)

Bank 1 (256K x 4 bit) = 128KB ---------- ( 1Mx1)
Bank 2 (256K x 8 bit) = 256KB ---------- ( 1Mx2)
Bank 3 (256K x 12 bit) = 384KB --------- ( 1Mx3)
Bank 4 (256K x 16 bit) = 512KB --------- ( 1Mx4)

with 256x4 - each bank would be 1Mx4 (0.5mb) giving you 2Mx16 with 4 banks fully populated = which is 2MB ?

Bank 1 (1M x 4 bit wide ) = 0.5MB ---------- ( 256x16)
Bank 2 (1M x 8 bit wide ) = 1.0MB ---------- ( 512x16)
Bank 3 (1M x 12 bit wide) = 1.5MB ---------- ( 768x16)
Bank 4 (1M x 16 bit wide) = 2.0MB ---------- ( 1Mx16)


now the nubers are little out in my head because to use 256x1 would require the card to be able auto config its own ram and access it differently compared to 256x4 - so can anyone confirm the above rambling ?

1. Have I got my math wrong (yes it is a sunday)
2. Have amiga.resource been given the wrong info?
3. Did some one decide to put some random 256x1 intel DIP DRAM's for just the photo shoot?
4. has anyone got a picture of this card with 2MB installed?

thanks for reading =)

The P21010 is a 1M x 1, not 256K x 1

http://www.datasheetarchive.com/P21010-datasheet.html

[Zetr0]

man this plot thickens and thickens

[Zetr0]

Has anyone got a manual for the GVP SCSI+2?