Search found 2221 matches

by 1024MAK
Tue Feb 19, 2019 10:20 am
Forum: ZX BASIC
Topic: How to iterate the iteration
Replies: 5
Views: 70

Re: How to iterate the iteration

As BASIC variables are CLEARed when RUN is used, if you wish to retain a value in between RUNs, you can store it in an area of RAM that BASIC will leave alone. So for example, on a ZX81, in a REM statement in the first line of a program. 3102715E-3336-4218-8813-78FE0245D5C5.jpeg Note that I entered ...
by 1024MAK
Tue Feb 19, 2019 1:05 am
Forum: ZX BASIC
Topic: How to iterate the iteration
Replies: 5
Views: 70

Re: How to iterate the iteration

If you keep your program as it is, instead of using RUN to run it a second (or third) time, you instead use GO TO 15, it will do what you want. You will need to add a CLS or a SCROLL to prevent running into the bottom of the screen if you use GO TO 15 too many times though.

Mark
by 1024MAK
Sun Feb 17, 2019 12:21 pm
Forum: Hardware
Topic: ZX81 HDMI interface using Raspberry Pi Zero
Replies: 7
Views: 280

Re: ZX81 HDMI interface using Raspberry Pi Zero

Just a thought, but if you already have a ZX CCB or ZX Vid comp video pcb installed, would you be able to bypass the comparator circuit altogether, and feed the signal directly into the RGB to HDMI? No, if you are saying what I think you are saying. As I understand it, the PI needs separate video a...
by 1024MAK
Sat Feb 16, 2019 11:20 am
Forum: Development
Topic: Generating a hi res display using flat assembler
Replies: 6
Views: 160

Re: Generating a hi res display using flat assembler

What I still don't understand properly is how the ULA suddenly takes over <snip> The ULA only “intercepts” the Z80 CPU instruction fetch when the CPU attempts to execute code in the upper area of RAM. That is, when the address is 0xC000 or above. If the CPU tries to execute the display file in the ...
by 1024MAK
Tue Feb 12, 2019 6:38 pm
Forum: Hardware
Topic: ZX 128k +2 french " grey " : scart cable ...
Replies: 9
Views: 515

Re: ZX 128k +2 french " grey " : scart cable ...

The CPC computer range runs on a single +5V supply. The +12V for the CPC664 and CPC6128 being required for the disk drive only. As such, no, normally there is no need to replace any electrolytic capacitors as preventive maintenance in these computers. The monitors may be a different story though. Ma...
by 1024MAK
Sun Feb 10, 2019 2:41 pm
Forum: Hardware
Topic: ZX 128k +2 french " grey " : scart cable ...
Replies: 9
Views: 515

Re: ZX 128k +2 french " grey " : scart cable ...

I think some clarification is needed. In a ZX80 or a ZX81, all the logic on the main/motherboard runs from the +5V rail. Unless the computer fails to work, there is no need to change any of the capacitors on the computers main / motherboard. And even then capacitor failure that results in a non-work...
by 1024MAK
Sun Feb 10, 2019 1:21 am
Forum: Emulators
Topic: missing rom
Replies: 1
Views: 202

Re: missing rom

The ROM for the ZX81 (bug fixed version) and the TS1000 are the same.

Mark
by 1024MAK
Thu Feb 07, 2019 2:26 am
Forum: Hardware
Topic: Faulty ZX81 logic probe results
Replies: 10
Views: 1034

Re: Faulty ZX81 logic probe results

Well done :D

I’m glad that you are having fun! :lol:

Mark
by 1024MAK
Mon Feb 04, 2019 11:05 pm
Forum: Hardware
Topic: Interesting ZX81 keyboard
Replies: 4
Views: 240

Re: Interesting ZX81 keyboard

Andy Rea wrote:
Mon Feb 04, 2019 5:55 pm
Would you like a spoon :lol:
Nah, just attempting a forum perpetual motion machine... :lol: