Search found 138 matches

by psmart
Thu Jul 22, 2021 9:41 am
Forum: Hardware
Topic: Any way to improve the screen brightness of an MZ80B
Replies: 6
Views: 2950

Re: Any way to improve the screen brightness of an MZ80B

That is strange to not see the flyback lines, I have contrast turned to max and brightness about half way, any more and the flyback lines appear. I made the decision to replace all given that electrolytics only have a limited lifespan as they dry out and most sources limit their useable life around ...
by psmart
Wed Jul 21, 2021 8:51 pm
Forum: Hardware
Topic: Any way to improve the screen brightness of an MZ80B
Replies: 6
Views: 2950

Re: Any way to improve the screen brightness of an MZ80B

Bit more info, the 80B monitor is identical to the 80A and 2000. Try adjusting the brightness (R2008 - variable resistor) but if it goes too bright and you see the flyback lines then back it off until the main screen is dark. Try also adjusting the contract, this makes the characters brighter in gen...
by psmart
Wed Jul 21, 2021 11:20 am
Forum: Hardware
Topic: Any way to improve the screen brightness of an MZ80B
Replies: 6
Views: 2950

Re: Any way to improve the screen brightness of an MZ80B

I recently decided to replace all the capacitors on my MZ-80A screen as the screen size was getting vertically smaller and couldnt be compensated with the vertical size/linearity (any attempt just started scolling). After completion, screen is back to full size, as per photo below and brightness is ...
by psmart
Wed Jul 21, 2021 11:12 am
Forum: Hardware
Topic: MZ80B - BootRom Disc
Replies: 12
Views: 7600

Re: MZ80B - BootRom Disc

Cool project, definitely an alternative to the B/2000/2500 cassette drive is needed, they all suffer the same fate.

I'm in the process of getting the cassette cogs 3d printed as they all seem to crack on the clutch/flying drive cog, but to have a backup drive is excellent.
by psmart
Thu Jul 08, 2021 9:34 pm
Forum: Hardware
Topic: MZ-700 Blank Key.
Replies: 35
Views: 13556

Re: MZ-700 Blank Key.

No problem, I located a company in Leeds who can scan and print, hoping to get it sorted next week. Was just about to post the text below but probably not relevant now, great news, all working :) The MZ700 cassette decks that have passed my way, especially if I've changed the drive belt, need calibr...
by psmart
Sun Jul 04, 2021 9:21 pm
Forum: Hardware
Topic: MZ-700 Blank Key.
Replies: 35
Views: 13556

Re: MZ-700 Blank Key.

Looking through your blog, an impressive set of machines has passed your way. I suddenly hit on the RG-3915 and it got me thinking, do you have sources for spare cogs? Reason is I'm building my collection and have an MZ-2000 and MZ-2500 both using the exact same cassette mechanism. A triple solenoid...
by psmart
Sun Jul 04, 2021 9:10 pm
Forum: Hardware
Topic: MZ-80b FI/O to HxC Cable
Replies: 64
Views: 33213

Re: MZ-80b FI/O to HxC Cable

If you can lock the PC to a fixed speed then the assembler source code (provided) can be modified - it is supposed to use the 8254 timer but on the scope the marks/spaces were quite a bit out, ie 390uS instead of 366uS and the scope was dancing, even on the lead in, it couldn't get a fixed sync (had...
by psmart
Sun Jul 04, 2021 9:02 pm
Forum: Hardware
Topic: MZ-700 Blank Key.
Replies: 35
Views: 13556

Re: MZ-700 Blank Key.

Very nice, sometimes we rush into 'new tech' we forget what gems existed, but the price of the caps, 50pounds!!! Yep, just PM me when you want it sending. The X68K I tried multiple tips until I found a balance, not too fine or thick, 400'c, nip the tantalums off, wet it with fresh solder and solder ...
by psmart
Sun Jul 04, 2021 8:42 pm
Forum: Hardware
Topic: MZ-80b FI/O to HxC Cable
Replies: 64
Views: 33213

Re: MZ-80b FI/O to HxC Cable

One of the things which is needed is a disk to tape copy utility, that way it is easy to regenerate the cassettes. I tried to get the PC program on original.sharpmz.org running on a T30 to generate 80B/2000 cassettes but wasted a day with no success, guess you need an AT or 386 for it!
by psmart
Sun Jul 04, 2021 8:39 pm
Forum: Hardware
Topic: MZ-700 Blank Key.
Replies: 35
Views: 13556

Re: MZ-700 Blank Key.

Cool :) - well done. One of the first things I do is check the voltage as some of the MZ-700's have been down to 4.69V, a tweak of the var-resistor in the PSU sorts it out. The tantalums of the era are known for going short circuit and the electrolytics drying out, cool analysis. I re-capped an X68K...