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schlae / snark-barker-mca

A Sound Blaster compatible sound card for Micro Channel bus computers
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D87c51 does not work! #12

Open vossi1 opened 2 years ago

vossi1 commented 2 years ago

Hi, i just tested some intel D87c51 mc's with dsp2.02 in two snark barkers and they don't work. No respond of any dsp test. My at89s51's work great.

What type is the original mc in a sb1 or clone card?

EDIT: I just found out that the seller shipped me D87c51-FA ! These seem not to be compatible. They have double rom+ram and are and additional timers and a counter.

I ordered real d87c51 now...

Christian

vossi1 commented 2 years ago

Negative Update:

I got intel TD87C51, D8751-H and 3x Signetics/Philips SC87C51CCF40. All are fully 80c51 compatible!

None of them works in the SB MVC. Get DSP ID gives -1.255

But why???

schlae commented 2 years ago

Are you using sbdiag for that test? It will likely take some more detective work to track this down. Do you have a logic analyzer?

vossi1 commented 2 years ago

I use sbdiag and test.sbc also doesn't find the card at 220. OPL2 sound in Arkanoid2 works.

Have you modified the dsp2.02 software? Or ist it the original creative 80c51 file?

I have a LA. What signals do you need to check?

schlae commented 2 years ago

Look at ISA_RD, ISA_WR, DSP_WRITE, DSP_READ to get an idea of the timing of the mailbox reads and writes. I have a feeling the issue is with the mailbox (U19/U18) or possibly the associated buffer U2. What logic family did you use for those chips? They should be fast, like AHCT, ACT, or F.

vossi1 commented 2 years ago

We previously talked about the TTL-speed ;) I have only ALS chips.

I just looked in the schematics and the d87c51 intel datasheet. EA/VPP should be +5V and ALE/Prog ans PSEN should be open - so all ok - even for an old 87c51. What chip does creative used on a sb 1.0? I sadly have only some 2.0 with plcc chips.

elosha commented 2 years ago

@schlae AT89S51 is getting difficult to order. Which MCS-51 devices have you found to work in SB/SB-MCA?

vossi1 commented 3 months ago

Update: I got a real Sound Blaster 1.5 and tested my 87c51 Controllers from Intel and Philips there - all working perfectly. The Intel 80c51FAD with double ram/rom works and the Philips full 80c51 compatible also ok. But sadly not in the Snark Barker MCA - here only Atmel work. - Why ever?