Die Suche ergab 23 Treffer

von rune
12.07.2019, 17:12
Forum: Sinclair ZX81
Thema: ZXNU
Antworten: 5
Zugriffe: 1226

Re: ZXNU

Yes, I tried the LS version in both of my ZX NUs and got the same effects.In fact I tried 3 LS versions - all the same.

Also, changing the Z80 between the 6 or 7 I have made the effects more or less worse. But the weirdness was definitely IC14.

Dave
von rune
12.07.2019, 13:19
Forum: Sinclair ZX81
Thema: ZXNU
Antworten: 5
Zugriffe: 1226

Re: ZXNU

hi Joachim it was the LS variant. It gave a perfect picture, but couldnt stop it rolling. The HCT version fixed it. The Menu screen with black on white didnt roll, but was low by about 8 lines. The white on black rolled badly. The ZX81 screen jumped in 12 or so line incrememnts, but a loop to print ...
von rune
11.07.2019, 20:20
Forum: Sinclair ZX81
Thema: ZXNU
Antworten: 5
Zugriffe: 1226

Re: ZXNU

Problem solved, it was IC14 causing the problem.
von rune
04.07.2019, 21:39
Forum: Sinclair ZX81
Thema: ZXNU
Antworten: 5
Zugriffe: 1226

ZXNU

Hello, I have built my second ZX NU which boots and works OK except for a couple of things: 1 - The first screen is mostly stable, but has rolled so that the bottom line appears at the top. 2 - If I select ZX81 or H4th, the screen rolls in jumps of about 2/3 of a screen . I've tried changing the Z80...
von rune
24.03.2019, 19:00
Forum: Sinclair ZX81
Thema: Z80 PIO
Antworten: 9
Zugriffe: 1632

Re: Z80 PIO

Thanks again Heinz, I have that done. It takes a while to translate the PIO manual to English. Sometimes Google translate causes even more problems.

The OUT commands are good now. I will look at IN later. For now, I'm happy it works.

Dave
von rune
24.03.2019, 14:06
Forum: Sinclair ZX81
Thema: Z80 PIO
Antworten: 9
Zugriffe: 1632

Re: Z80 PIO

Hi Heinz

So far only ZX81 using Joachins demo/test programs. I'll look at H4th next.

Question - The address information you pointed me to shows 4 values for each jumper ABCDEFGH

Using A, I have C7 CF D7 DF. I saw D7 DF were for OUT, are C7 CF for IN? Or maybe something different?

Dave
von rune
24.03.2019, 12:08
Forum: Sinclair ZX81
Thema: Z80 PIO
Antworten: 9
Zugriffe: 1632

Re: Z80 PIO

Hello Heinz thanks, I've just got it working. I used 570 Ohm resistors as the example of (other) LED wiring I found online said to use 407 Ohms. It works, but I have a dead LED - I had to use a mixture of what was in my box so greens, reds and white :) Got a video, but its a bit too large to send/po...
von rune
23.03.2019, 23:29
Forum: Sinclair ZX81
Thema: Z80 PIO
Antworten: 9
Zugriffe: 1632

Re: Z80 PIO

Paul, I hope not... The connector is between the two white vertical lines. I have 5 positions to the left and 4 to the right. Left to right... Across the top is d7, /ramcs, slot, d0, d1 etc and on the bottom is 5v, 9v, slot, gnd, gnd, clock etc. This matches the Zeddy manual so I think/hope its all ...
von rune
23.03.2019, 20:46
Forum: Sinclair ZX81
Thema: Z80 PIO
Antworten: 9
Zugriffe: 1632

Z80 PIO

Hello everyone. I have built a ZX81 I/O board I got from Heinz. I think its designed by Joachim, but I may be wrong. A photo of the board should be attached 20190323_164151.jpg Can anyone point me towards documentation or assist on how to use it please. Even details on how to test if its working wou...
von rune
28.02.2019, 20:03
Forum: Sinclair ZX81
Thema: ZX NU - H4th - VDrive
Antworten: 0
Zugriffe: 1742

ZX NU - H4th - VDrive

Hi, I'm not sure if this has been done for H4th/VDrive as my German isnt good enough to search the forums sensibly. I've written some new Forth words to extend the commands available for H4th & VDrive users on the ZX NU. All work except the SEK command, which I havent tested yet. Here they are... : ...
von rune
02.05.2016, 21:46
Forum: Sinclair ZX81
Thema: ZX 81 NU - Memory
Antworten: 2
Zugriffe: 3345

Re: ZX 81 NU - Memory

Thanks Siggi,

using the additional memory is way beyond my capabilities just now. But its nice to know that the normal RAM covers 8-64k.

Dave
von rune
02.05.2016, 15:54
Forum: Sinclair ZX81
Thema: ZX 81 NU - Memory
Antworten: 2
Zugriffe: 3345

ZX 81 NU - Memory

Hi, I now have my ZX NU running perfectly. Problem was a bad capacitor on the power supply. So now I need to find out more about the computer. First thing is that the menu screen tells me there is 80Kb of RAM. How is this allocated? If its mapped from 8K to 64K there is still 24K left over. Can the ...
von rune
18.04.2016, 17:43
Forum: Sinclair ZX81
Thema: ZX 81 - Assembler
Antworten: 8
Zugriffe: 4787

Re: ZX 81 - Assembler

I think it isn't that difficult. So you say the number is printed in general but not it's value as expected ? Then you did maybe swap data/registers. If you set STK-END and call that routine than it should be printed. The FP STACK is processed from bottom to top, so only STK-END has to be set at th...
von rune
18.04.2016, 12:55
Forum: Sinclair ZX81
Thema: ZX 81 - Assembler
Antworten: 8
Zugriffe: 4787

Re: ZX 81 - Assembler

That toolkit has a DUMP routine, which prints all variables and its values onto screen. Enter RAND USR DUMP after you have loaded the toolkit. The 64K version runs in ram at 14-16K, the 16K version above ramtop. Hope that helps Hi Siggi, thats exactly what Im trying to do. The good news is I found ...
von rune
17.04.2016, 23:46
Forum: Sinclair ZX81
Thema: ZX 81 - Assembler
Antworten: 8
Zugriffe: 4787

Re: ZX 81 - Assembler

Thanks for replying Karl. What Im trying to do is this... I have the address of the first byte of a (5 byte) floating point number in HL. I want to print this number. I assume I need to move the 5 bytes onto the calculator stack and then call the FP print routine. I'll have a look at the methods you...
von rune
17.04.2016, 20:52
Forum: Sinclair ZX81
Thema: ZX 81 - Assembler
Antworten: 8
Zugriffe: 4787

ZX 81 - Assembler

Hello, Im trying to write a small machine code routine which needs to print a floating point number. The number is in the standard Sinclair format - 5 bytes of mantissa and exponent. Can anyone tell me how to do this? I am searching through the ROM Disassembly book and searching the web but not find...
von rune
15.04.2016, 23:01
Forum: Sinclair ZX81
Thema: ZX81-Kompatibler aus Standardbauteilen: ZX81NU
Antworten: 472
Zugriffe: 223748

Re: ZX81-Kompatibler aus Standardbauteilen: ZX81NU

Ooops, mine also says P2. Its been a long week.

Just a couple more little problems to sort and I will be 100% complete.
von rune
15.04.2016, 19:58
Forum: Sinclair ZX81
Thema: ZX81-Kompatibler aus Standardbauteilen: ZX81NU
Antworten: 472
Zugriffe: 223748

Re: ZX81-Kompatibler aus Standardbauteilen: ZX81NU

Hi, I have now got my ZX81 NU working with the micro drive and vDrive. After checking countless connections I decided to double check the chip I was sent and it was wrong. Instead of sending me a 25LC1024 I was sent a 24LC1025. The seller did show the correct chip but I never spotted the other code ...
von rune
04.04.2016, 22:13
Forum: Sinclair ZX81
Thema: ZX81-Kompatibler aus Standardbauteilen: ZX81NU
Antworten: 472
Zugriffe: 223748

Re: ZX81-Kompatibler aus Standardbauteilen: ZX81NU

Hello Paul Yes, I have tried with or without the VDrive. There's no difference. Its almost as if the vDrive wasn't there. How do you initialise the micro disk? Heinz told me to press W at the initial screen. All those 01010101s makes me think its writing to the screen instead of the disk. Yes, I did...
von rune
04.04.2016, 21:52
Forum: Sinclair ZX81
Thema: ZX81-Kompatibler aus Standardbauteilen: ZX81NU
Antworten: 472
Zugriffe: 223748

Re: ZX81-Kompatibler aus Standardbauteilen: ZX81NU

Hi, I am still having problems with the ZX NU board. It now runs nicely but there is a problem the micro drive and VDrive so I cant save any programs. The vDrive doesnt seem to work at all. 1st strange thing is I press W on the menu screen, SPI Write is displayed the page after page of 0101010101010...
von rune
03.04.2016, 08:25
Forum: Sinclair ZX81
Thema: ZX81-Kompatibler aus Standardbauteilen: ZX81NU
Antworten: 472
Zugriffe: 223748

Re: ZX81-Kompatibler aus Standardbauteilen: ZX81NU

The documentation tried to tell that if you use a HCT245 it's normal that a Memotech Keyboard won't work (like on the ZX80). So alternatively you can use a LS641 (which I also do) so you will be able to use the Memotech keyboard (as a well known example of a keyboard with external interface) and al...
von rune
02.04.2016, 21:36
Forum: Sinclair ZX81
Thema: ZX81-Kompatibler aus Standardbauteilen: ZX81NU
Antworten: 472
Zugriffe: 223748

Re: ZX81-Kompatibler aus Standardbauteilen: ZX81NU

Hi Paul, thanks for the welcome. I now have a 99.9% working ZX NU. I had used HCT245 IC in IC 7. When I managed to translate the document I realised this was for Memotech keyboards. So I swapped with LS621 and now all keys work. One last question... Sometimes when I start the ZXNU the display shows ...
von rune
02.04.2016, 19:35
Forum: Sinclair ZX81
Thema: ZX81-Kompatibler aus Standardbauteilen: ZX81NU
Antworten: 472
Zugriffe: 223748

Re: ZX81-Kompatibler aus Standardbauteilen: ZX81NU

Hello, this is my first post on the forum and I am in need of some help. Apologies for asking for help before introducing myself. I have built a ZX81 NU which is 99% working. I have one last problem with the keyboard. I am going use the PCB with a DK'tronics keyboard which works perfectly with the c...