Search found 990 matches

by XavSnap
Wed Sep 23, 2020 6:00 pm
Forum: SALES
Topic: RS232 Interface (8255 Chip) £30
Replies: 7
Views: 2306

Re: RS232 Interface (8255 Chip) £30

Hi,
Yes, it's an (another!) Centronics card… too many datas on the socket, it's a female subd25 and there's no cristal/max232 components.
But, with a 8255, you can send a serial data on the socket… with a good zx81 program.
by XavSnap
Wed Sep 23, 2020 3:42 am
Forum: Emulators
Topic: [Vb81] Test release.
Replies: 32
Views: 21015

Re: [Vb81] Test release.

New release 23/09/2020.
* Memotech IF Centronics fixed (New ROM dumped by Erm/Bios patch)
by XavSnap
Wed Sep 23, 2020 3:38 am
Forum: ZX BASIC
Topic: SCROLL and MCODER II
Replies: 5
Views: 1943

Re: SCROLL and MCODER II

Hi, Try to type this Basic code to load the ASM program: ADD= ASM Scroll start code. (memory offset 32300, but you can store it in the PRbuff @ 16445 if the printer is not use!...only 29bytes) But, i don't know if the MCoder2 use this memory segment. 10 LET ADD=32300 20 LET C$="2A0C40EB2A0C400121000...
by XavSnap
Tue Sep 22, 2020 9:19 pm
Forum: SALES
Topic: Memopak Centronics Interface, plus another.
Replies: 15
Views: 1774

Re: Memopak Centronics Interface, plus another.

"Real" size pictures: http://zx81.ordi5.free.fr/memotech/MT07_IF/Memotech_If_1.jpg http://zx81.ordi5.free.fr/memotech/MT07_IF/Memotech_If_2.jpg http://zx81.ordi5.free.fr/memotech/MT07_IF/Memotech_If_3.jpg http://zx81.ordi5.free.fr/memotech/MT07_IF/Memotech_If_4.jpg http://zx81.ordi5.free.fr/memotech...
by XavSnap
Tue Sep 22, 2020 7:06 pm
Forum: SALES
Topic: Memopak Centronics Interface, plus another.
Replies: 15
Views: 1774

Re: Memopak Centronics Interface, plus another.

Thanks to all contributors.
by XavSnap
Tue Sep 22, 2020 7:03 pm
Forum: SALES
Topic: Memopak Centronics Interface, plus another.
Replies: 15
Views: 1774

Re: Memopak Centronics Interface, plus another.

Hi,
The Memotech is now complet.
Capture_ifrom5.JPG
The last Rom, without the BIOS memory segment : http://www.zx81stuff.org.uk/zx81/hardware/MemopakIF

The new ROM:
MemotechCIF.zip
(602 Bytes) Downloaded 10 times
:ugeek:

I'm working to had this hardware to Vb81.
by XavSnap
Tue Sep 22, 2020 6:45 pm
Forum: SALES
Topic: Memopak Centronics Interface, plus another.
Replies: 15
Views: 1774

Re: Memopak Centronics Interface, plus another.

Many Thanks Erm,
:shock:

It's a fast Dump !
:lol:

About 108 bytes changed:
Capture_ifrom4.JPG

Dump in the A$ variable:
Rom_IF.p
(4.97 KiB) Downloaded 7 times
Bios binary:
Bios_IFC.zip
(6.76 KiB) Downloaded 7 times
by XavSnap
Tue Sep 22, 2020 5:13 pm
Forum: SALES
Topic: Memopak Centronics Interface, plus another.
Replies: 15
Views: 1774

Re: Memopak Centronics Interface, plus another.

Hi,
I typed the bytes display with the BIOS compare tool.

Original ROM, with its zero bytes readable in the bios:
Capture_ifrom1.JPG
Typed bytes read from the BIOS memory bloc.(hardware relocation)
Capture_ifrom2.JPG
62 bytes misted in the dumped Rom...
Capture_ifrom3.JPG
by XavSnap
Tue Sep 22, 2020 12:50 am
Forum: SALES
Topic: Memopak Centronics Interface, plus another.
Replies: 15
Views: 1774

Re: Memopak Centronics Interface, plus another.

Hi Erm, I'm sorry, i put the wrong dump program ! It dumped the $2000 to $3000 memory segment… The right program will (REALLY) scan the 0-2000 memory offset. P & Wav: BiosDump.zip LOAD it, and wait the "9/4" (STOP AT LINE 4) And Save it (SAVE"DUMP") Your previous wav was clean and working. I'm sorry...
by XavSnap
Mon Sep 21, 2020 12:08 pm
Forum: SALES
Topic: Memopak Centronics Interface, plus another.
Replies: 15
Views: 1774

Re: Memopak Centronics Interface, plus another.

Thanks Erm, The RomCheck tool is an ASM program how read the original BIOS datas from a REM and get ROM BIOS. It will give you all values/address changed by the If hardware. The Bios backup retrieve the Bios $0-$2000 and store it in a DIM value. Run the program and save it as a P file, the Bios will...