Search found 151 matches

by kodak80
Tue Dec 10, 2019 8:27 am
Forum: DiagROM
Topic: DiagROM for ST
Replies: 120
Views: 15246

Re: DiagROM for ST

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 th...
by kodak80
Sun Dec 08, 2019 3:31 pm
Forum: MONGREL H4 USER BUILDS
Topic: kodak80 H4 build (x2)
Replies: 44
Views: 1202

Re: kodak80 H4 build (x2)

Yes, patch on the SIMM pins was done.

After re-soldering the SIMM socket, I now have one address on SIMM and the other when using the Falcon RAM card.
by kodak80
Sun Dec 08, 2019 12:35 pm
Forum: MONGREL H4 USER BUILDS
Topic: kodak80 H4 build (x2)
Replies: 44
Views: 1202

Re: kodak80 H4 build (x2)

Removed the SIMM and re-tested the address and without RAM. This now reads as:
1111111100001110

Now re-soldering the SIMM pins...
by kodak80
Sun Dec 08, 2019 12:01 pm
Forum: MONGREL H4 USER BUILDS
Topic: kodak80 H4 build (x2)
Replies: 44
Views: 1202

Re: kodak80 H4 build (x2)

Okay, I have resoldered the ROM pins and check continuity and resistance on address and data pins and they all test fine but still getting the wrong address. Any suggestions?
by kodak80
Sun Dec 08, 2019 11:25 am
Forum: MONGREL H4 USER BUILDS
Topic: kodak80 H4 build (x2)
Replies: 44
Views: 1202

Re: kodak80 H4 build (x2)

Icky wrote:
Sun Dec 08, 2019 9:28 am
Good spot @kodak80. So thats a 1K1 pull-up on FC2 :)
I just bent up one of the SIL pins to remove the double-up.
by kodak80
Sun Dec 08, 2019 11:24 am
Forum: MONGREL H4 USER BUILDS
Topic: kodak80 H4 build (x2)
Replies: 44
Views: 1202

Re: kodak80 H4 build (x2)

My address being read from ROM is

0000000000001110

Which is wrong so just checking the soldering on the TOS ROM pins.
by kodak80
Sun Dec 08, 2019 9:27 am
Forum: MONGREL H4 USER BUILDS
Topic: kodak80 H4 build (x2)
Replies: 44
Views: 1202

Re: kodak80 H4 build (x2)

exxos sorry, another question. We have been working through you testing guide and AS and DTACK are both going high as expected but my board is still only showing white screen and no floppy access. All pull-ups are fine, and cpu puns check out as per testing guide so need some further pointers. The ...
by kodak80
Sun Dec 08, 2019 8:51 am
Forum: MONGREL H4 USER BUILDS
Topic: kodak80 H4 build (x2)
Replies: 44
Views: 1202

Re: kodak80 H4 build (x2)

@exxos Any reason FC2 has a pull up on both RP5 and RP8? Pin 9 on both SILs.
by kodak80
Wed Dec 04, 2019 4:08 am
Forum: MONGREL H4 USER BUILDS
Topic: derkom's attempt
Replies: 139
Views: 2483

Re: derkom's attempt

Well done on getting this output. Need to check my soldering work.
by kodak80
Tue Dec 03, 2019 12:38 pm
Forum: MONGREL H4 USER BUILDS
Topic: kodak80 H4 build (x2)
Replies: 44
Views: 1202

Re: kodak80 H4 build (x2)

Yes, I have a 2 channel scope which I can use so will look to work through your guide over the next few nights.

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