Struggling wih a T130 SCSI option ROM

[Nafartarra]

Hi all!

This afternoon I started doing experiments with the objetive of booting my DTK XT board from my Trantor T130 SCSI adaptor.
Since I don't have any EPROM eraser, i built a Flash ROM board after getting the idea from Lo-Tech 8 bit ROM board, I made it using a old Pentium bios and some glue logic for the comparitor. The flash ROM works great, I've been able to program it and make the XT-IDE Bios boot.

I've downloaded the ROM for the T130 from here http://www.minuszerodegrees.net/rom/rom.htm , but I heven't been able to make the ROM work.
The only thing that I get is "Scratch RAM Error" on the display and the computers boot from floppy as usual.
The ROM has that string inside, but I haven't been able to think what makes it to do that, since I'm very bad reading machine code.

Does somebody know something about this error?

Thanks!!!!

 

[Chuck(G)]

I assume that you have the PAL installed that goes in the 20-pin socket just above the BIOS PROM. There were a great number of T130s sold without either the PAL or the PROM for use in scanner or CD-ROM interfacing.

 

[Nafartarra]

Thanks Chuck!

No... I don't have that chip, I've watched the circuit ob the T130 and it seems that tha ROM a that chip play some mayor part on the circuit...
I supose that the PAL is programmed, so even if I found the chip, I would have to program it, or I'm wrong?

 

[Chuck(G)]

You need the chip if you are to use the BIOS. See my blog entry on this chip for more information.

 

[Nafartarra]

Thanks Chuck!!!
While I was reading your blog entry I realized that the PAL16L8 sounded familiar to me, it was in the box of the IC that I unsoldered from the ISA board (a Trantor 16Bit IDE controller) that I'm using as base for the programable flash ROM, so I've got work for this afternoon.
The last cuestion is that if it is necesary that the option ROM has to be placed on the T130 board or can I put it in the Flash ROM board that I've built?

Edit: I realized that the 16L8 is not reprogramable, so I will have to buy a new one or a GAL or emulate the part of the chip that doesn't drive the ROM with a EPROM and 74xxx logic.

Thanks everyone!!!!