Search found 38 matches

by S_U_C
Wed Feb 17, 2021 11:26 pm
Forum: Hardware
Topic: MZ-80B project (Floppy Disk I/O Card cloning!)
Replies: 17
Views: 6617

Re: MZ-80B project (Floppy Disk I/O Card cloning!)

Hi I found a large A3 scan of the MZ-80A floppy disk card, this will work in the B if you dissable the CS/CE to the EPROM IC 3 PIN 8 to IC 5 PIN 1. add pull-up resister to IC 5 PIN 1
by S_U_C
Wed Feb 17, 2021 11:17 pm
Forum: Buy/sell
Topic: WTB: MZ80B FDD controller card
Replies: 4
Views: 782

Re: WTB: MZ80B FDD controller card

I was correct there is one track that has to be cut to convert the A card to a B card the EPROM's CS/CE signal IC 3 PIN 8 to IC 5 PIN 1
IC 5 PIN 1 will need a pull-up resistor adding. see images
by S_U_C
Wed Feb 17, 2021 11:07 pm
Forum: Other
Topic: Original software from SUC for MZ 800
Replies: 4
Views: 307

Re: Original software from SUC for MZ 800

Hi the Sharp Users Club had died 1980-2020 due to lack of members, Last SUC magazine 2020 vol2 November issue is still at the printers (lockdown problems) I have a large selection of tape and disks for various Sharp machines. I have an 800 basic disk marked PIXEL (EPSON) but can not access it, as al...
by S_U_C
Wed Feb 10, 2021 5:53 pm
Forum: Buy/sell
Topic: WTB: MZ80B FDD controller card
Replies: 4
Views: 782

Re: WTB: MZ80B FDD controller card

Do you want to run CP\M or do you want to extract data from the disks? I have a KroFlux and can read the disks except the boot sector, but I know what it is anyway. And I have my own software that can mount the KroFlux file and display directories and extract files. The Mz-80A FD card will work in t...
by S_U_C
Thu Sep 10, 2020 9:20 am
Forum: Hardware
Topic: Mz80-A no cursor
Replies: 8
Views: 2214

Re: Mz80-A no cursor

I had a similar fault on a MZ80K. I was the flash timer is not working. The K used a 555 timer and the MZ80A uses a 556 (IC51)+ caps C39,C40 On the A the start up order is the setup clear screen print ** MONITOR SA-1510 ** test for he USER ROM/RAM at $E800 (IC43 next to the Monitor ROM) print Newlin...
by S_U_C
Wed Jul 15, 2020 2:45 pm
Forum: Demoscene
Topic: MZ-700 demos
Replies: 79
Views: 34448

Re: MZ-700 demos

Note: just to make things more interesting The MZ-80K and MZ80A ROM and RAM opcode timings are the same. But the MZ700 runs opcodes faster in RAM than ROM as the LSI chip controls the /WAIT ine of the CPU and it adds 1 extra T-cycle to the opcodes in ROM. This speeds up the tape read/write routines ...
by S_U_C
Mon Jun 15, 2020 10:06 am
Forum: Hardware
Topic: MZ 80K repair project
Replies: 24
Views: 8378

Re: MZ 80K repair project

Sounds like the horizontal synch has failed.
Check test points 13 to 21 on the video board with an oscilloscope, ( see page 40 of the MZ80K Service Manual) and compare with traces on pages 19/20.
by S_U_C
Wed Jun 10, 2020 2:20 pm
Forum: Hardware
Topic: MZ 80K repair project
Replies: 24
Views: 8378

Re: MZ 80K repair project

Check that capacitors C407 c406 c503 or c504 are OK. I can remember repairing a K power supply (that kept blowing fuses ) for MH in Weymouth many years ago by replacing the blue capacitors which are part of the voltage setting circuit. I think one was short circuited but we replaced all 4. ESR is sh...
by S_U_C
Mon Apr 06, 2020 11:26 am
Forum: Hardware
Topic: MZ700 video problem
Replies: 19
Views: 7108

Re: MZ700 video problem

Hi I have a MZ80K with the same problem. A static random screen, the pattern is always the same on power or reset. I reproduced the fault on another MZ80K by testing a RAM checker eprom that it did not work in the faulty machine. The both MZ80K could not see the eprom,the eprom was too slow 350ns. a...
by S_U_C
Wed Feb 19, 2020 9:50 pm
Forum: Other
Topic: SUC library
Replies: 5
Views: 3902

Re: SUC library

The Sharp User Club is still active.

If you want to join please contact John Duxbury at sharp.users.club@btinternet.com

He deals with membership enquiries.