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Re: DiagROM for ST

Posted: Tue Feb 12, 2019 4:57 pm
by PaulJ
Try another one just to make sure.. :D

Re: DiagROM for ST

Posted: Tue Feb 12, 2019 5:50 pm
by PhilC
PaulJ wrote:
Tue Feb 12, 2019 4:57 pm
Try another one just to make sure.. :D
I best go buy another 4 then as all my 27c010s are TI.

Re: DiagROM for ST

Posted: Tue Feb 12, 2019 6:43 pm
by PaulJ
Not that China is the issue but I ordered new ones from mouser. Its just happens that every time I get bitten by something wierd it comes from China.

Re: DiagROM for ST

Posted: Sun May 26, 2019 3:22 pm
by JezC
I've a couple of STFMs which don't boot to the desktop & thought that DiagROM might be a good way to try & see what needed doing.

I don't currently have any option but to fit the ROMs in place of the current TOS ROMs.
The boards have 2 ROMs fitted, TOS 1.02.

I have some 27c256 EPROMs (6x 250ns, 2x 150ns) plus a pair of 27c512s kindly supplied by RJ & was wondering if there is a build of DiagROM which will fit into these to diagnose the issues.

Is there a suitable image available for programming into any of the above?

Re: DiagROM for ST

Posted: Sun May 26, 2019 4:07 pm
by DoG
JezC wrote:
Sun May 26, 2019 3:22 pm
...I have some 27c256 EPROMs (6x 250ns, 2x 150ns) plus a pair of 27c512s kindly supplied by RJ & was wondering if there is a build of DiagROM which will fit into these to diagnose the issues.

Is there a suitable image available for programming into any of the above?
You got the github link in the first post. But I'm nice so here you go. Just get the hi and lo of the DiagRom for ST and pop them into the STfm instead of TOS 1.02.

I downloaded the DiagRom cart version and burnt it. Then put them in a cart. So never tried the above but it should work.

Re: DiagROM for ST

Posted: Sun May 26, 2019 5:20 pm
by JezC
Thanks for the reply.

When I downloaded the binaries for the ST they appeared to be just too big to fit in a pair of 27c512 - probably just a few K with a couple of strings and a couple of blocks of constant data values so I was hoping there might be a smaller image that would fit in the pair of 512k bit EPROMs I have available.

Slim chance probably, but I felt it worth asking.

Maybe the cart version is smaller? I don't have a board to use the cart versions directly or I'd give that a go.

Re: DiagROM for ST

Posted: Sun May 26, 2019 5:42 pm
by DoG
Yeah. Now that you mention it, the cart version is 128Kbyte (2 pieces of 64Kbyte roms).

But TOS 1.04 and below is 192Kbyte just like the DiagRom for ST is. Your 27C512 only fits 512Kbit (64Kbyte) so it won't fit as you said. You could split the DiagRom in 6 parts and burn it on your 27C256 (32Kbyte). You have to move threee solder pads on the main STfm board though.

EDIT: Not all STfm version boards have those three solder pads. So maybe not a smart option for your broken boards.

Re: DiagROM for ST

Posted: Mon May 27, 2019 10:44 am
by JezC
Hmm, sounds like what I really want is a build with the same image size as the cart version but as a replacement for the existing TOS ROMs.

Then I could program up the 27c512s and replace the existing ROMs to diagnose & fix the faults, then re-fit the original ROMs or even upgrade to 1.04 at some point.

Thanks again for the info...gives me some ideas to work towards.

Re: DiagROM for ST

Posted: Mon May 27, 2019 10:46 am
by exxos
JezC wrote:
Sun May 26, 2019 5:20 pm
When I downloaded the binaries for the ST they appeared to be just too big to fit in a pair of 27c512 -

A "pair" of ST ROM's is 27C1001 not 512... I have had diagrom running on a ST in place of the OS ROM's just fine.

Re: DiagROM for ST

Posted: Tue Dec 10, 2019 8:27 am
by kodak80
PaulJ wrote:
Tue Feb 12, 2019 12:53 am
Problem solved, had 2 HN27C4096 120ns eproms I got off eBay from China. One died in September last year. With the remaining chip it came down to the swapped byte image I tried in the bad half of the eprom rom over and over. It was programmed on two differient eprom programmers with no faults but the upper half of the eprom will not boot any image. Swapped bytes in the lower half and it work.. All this because I didn't want to make a first attempt in a one burn only chip. Shesh!!!

Thanks
I think I need to program a HN27C4096 to help me diagnose my H4 board. Can someone please confirm which file from Github I should use to program the chip?

Plan is to use this in the onboard PLCC44 socket and see what I get. Hoping someone can provide the file if it needs byte swapping.