Search found 462 matches

by tcat
Wed Apr 24, 2019 7:26 pm
Forum: Software & Programming
Topic: SCREEN1 = SYSVAR @ JSROM
Replies: 5
Views: 126

Re: SCREEN1 = SYSVAR @ JSROM

Hi Tobias, Jan, Thank you, that explains that nicely, but also makes me ask further. How about If slave blocks, channel tables, and heap blocks moved away from the screen1, appropriate system vars updated to point to a new home of tables concerned. Then at the screen top, remains a few lines ($144 b...
by tcat
Wed Apr 24, 2019 11:27 am
Forum: Software & Programming
Topic: SCREEN1 = SYSVAR @ JSROM
Replies: 5
Views: 126

SCREEN1 = SYSVAR @ JSROM

Hi, I have visualised 2nd vram (SCREEN-1) on JSROM, that maps over system variables. JSROM machines seem closest to Minerva. 10 REMark HEX(20000)=131072 .. SCREEN0, HEX(28000)=163840 .. SCREEN1 20 FOR s=0 TO 32764 STEP 4: POKE_L s+131072, PEEK_L(s+163840) 30 PAUSE vram2.png Bottom half seems almost ...
by tcat
Wed Apr 24, 2019 7:34 am
Forum: Hardware
Topic: Circuit diagram errata...
Replies: 6
Views: 371

Re: Circuit diagram errata...

Ah, haven't thought of that, production costs during board population and assembly, keeping pipelines filled. How about bona fide resistors R107/8 on top of ZX8302 ULA on Iss#6 boards, this bit I am not understanding, yet. I know they are part of documented mod (R102/3) for Iss#5, but do we see them...
by tcat
Tue Apr 23, 2019 4:01 pm
Forum: Hardware
Topic: Circuit diagram errata...
Replies: 6
Views: 371

Re: Circuit diagram errata...

http://www.dilwyn.me.uk/docs/hardware/QLschem.txt Hi, I have just spotted the update, many thanks for that. I wish to ask, do we see R107/108 flying on top of ZX8302 ULA for Iss#6 boards, what is the use of `0' Ohm resistors R102/103. What is the use of TC1 540pF trimmer, does it have to be adjuste...
by tcat
Fri Nov 09, 2018 6:13 pm
Forum: Hardware
Topic: Issue 6 board updates
Replies: 17
Views: 1984

Re: Issue 6 board updates

I made several Issue 6 PCB clones. For historical preservation. Hi, great work, did you also think of making Issue 5 PCBs? I own ISS6 QL, but I have always wondered which ISS is valued more? In the film making industry, sequals are rarely found as good to the original story. In u-electronics might ...
by tcat
Wed Nov 07, 2018 9:58 am
Forum: Software & Programming
Topic: SuperCharge Decompiler
Replies: 45
Views: 5039

Re: SuperCharge Decompiler

Hi Martin,

I have been away from QL scene for a while, however reading QL forum now and then, this project of yours caught my attention. I am curious what development tools and system you used for it, I can see some _libs but no executables, only _bas programs.

Cheers
Tomas
by tcat
Sun Nov 04, 2018 9:58 am
Forum: Wanted
Topic: WANTED - ZX Microdrive chassis
Replies: 1
Views: 369

WANTED - ZX Microdrive chassis

Hi,

Seeing rising polularity of `vDrive', that often use ZX Drive outer case as housing, there might be quite a few left over chassis out there.

These innards I am interested in for spares.

Many thanks
Tomas
by tcat
Sun Apr 08, 2018 2:22 pm
Forum: Hardware
Topic: All RAM chips destroyed??
Replies: 63
Views: 8077

Re: All RAM chips destroyed??

Hi Martyn, those JUx represent wire-links/zero-ohm resistors on the Iss-5 boards...They appear immediately between the ZX8302 and the right-hand ROM socket. ql-iss#5.jpg In the picture above I only located JU1,2,6 in the red rectangle, but manual refers to JU2,3,4. Is it just me looking at the wrong...
by tcat
Sun Apr 08, 2018 11:11 am
Forum: Hardware
Topic: All RAM chips destroyed??
Replies: 63
Views: 8077

Re: All RAM chips destroyed??

Hi, I have been following this topic with a great interest, while learning a lot about QL as well. It made me read several chapters from the service manual again, now with slightly more understanding. The chapter on firmware upgrade caught my attention. 4. Remove IC17 (74LS00). 5. Remove IC33 and IC...
by tcat
Thu Mar 15, 2018 6:00 pm
Forum: Hardware
Topic: Microdrive boards
Replies: 26
Views: 3533

Re: Microdrive boards

Dave wrote:Unfortunately, the company that made the heads went out of business a long time ago.


Ah bad luck, many thanks anyway.
Tomas