Search found 256 matches

by tzok
Tue Dec 22, 2020 2:13 pm
Forum: 8 BIT CORNER
Topic: A little bit of 8 Bit: 65XE upgrade to 128k RAM
Replies: 65
Views: 11760

Re: A little bit of 8 Bit: 65XE upgrade to 128k RAM

Not MMU, but EMMU. This is how 130XE (ECI) boards were configured for 65XE/800XE computers.

You could also replace the MMU, with another one or a programmed GAL replacement.
by tzok
Mon Dec 21, 2020 2:18 pm
Forum: 8 BIT CORNER
Topic: A little bit of 8 Bit: 65XE upgrade to 128k RAM
Replies: 65
Views: 11760

Re: A little bit of 8 Bit: 65XE upgrade to 128k RAM

These "resistors" mounted instead of EMMU are just jumpers (0 Ohm).
by tzok
Sun Dec 20, 2020 12:34 pm
Forum: 8 BIT CORNER
Topic: A little bit of 8 Bit: 65XE upgrade to 128k RAM
Replies: 65
Views: 11760

Re: A little bit of 8 Bit: 65XE upgrade to 128k RAM

Try to remove EMMU and cross-wire its socket, so the computer would behave as it had only 64 kB of RAM, and if it doesn't help, try to substitute MMU with another one or a GAL replacement (in 800 XL it was a PAL chip, so GAL replacement is 100% compatible).
EMMU_64k.png
EMMU_64k.png (212.64 KiB) Viewed 426 times
by tzok
Sat Dec 19, 2020 3:29 pm
Forum: 8 BIT CORNER
Topic: A little bit of 8 Bit: 65XE upgrade to 128k RAM
Replies: 65
Views: 11760

Re: A little bit of 8 Bit: 65XE upgrade to 128k RAM

Ok, I own any TMS4164-15NL, are they compatible with the first bank (42164-15) ? By markings, they are ok, but these chips look suspicious to me. Like they were sanded and re-engraved. Do they come from Aliexpress? I had similar glitches in my 800XL, and it was a faulty ANTIC chip (it was working c...
by tzok
Wed Dec 16, 2020 10:14 am
Forum: ELECTRONICS
Topic: 4 channel scope recommendations ?
Replies: 19
Views: 817

Re: 4 channel scope recommendations ?

If you want to observe just repetitive analog signals, then time equivalent sampling is ok, but if you want to catch a glitch in a digital signal, that occurs once in a few thousands (or more) cycles, then deep memory, and high real time sampling are crucial things to have. This old HP is just "deaf...
by tzok
Tue Dec 15, 2020 10:35 pm
Forum: ELECTRONICS
Topic: 4 channel scope recommendations ?
Replies: 19
Views: 817

Re: 4 channel scope recommendations ?

I remember those HP scopes from school, but for today's standards 54602B really isn't impressive. It is only 20 MSa/s, and for most time is working in time equivalent sampling. Its effective bandwidth for real time sampling is about 5 MHz, and has almost no memory (just 4 kPts). The entry level mode...
by tzok
Tue Dec 15, 2020 11:42 am
Forum: EXXOS WEBSTORE INFORMATION
Topic: VAT charges to EU states
Replies: 50
Views: 2390

Re: VAT charges to EU states

Graphics seem to be correct - within the EU, it is the seller (you) who pays VAT, and there are no custom fees. As for now, when you export goods from the non-EU to the EU countries, the VAT and customs fee are paid (or not) by the importer in the destination country. It is about to be changed, and ...
by tzok
Thu Dec 10, 2020 11:28 pm
Forum: HARDWARE DISCUSSIONS
Topic: Floppy 14-pin DIN Info
Replies: 6
Views: 388

Re: Floppy 14-pin DIN Info

I've printed some of these plugs, and they fit perfectly ok.
by tzok
Thu Dec 10, 2020 3:47 pm
Forum: HARDWARE DISCUSSIONS
Topic: Floppy 14-pin DIN Info
Replies: 6
Views: 388

Re: Floppy 14-pin DIN Info

My drawings are from "the nature", the dimensions are not super precise, especially the angles.

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