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

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dat-alex
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MZ-80B project (Floppy Disk I/O Card cloning!)

Post by dat-alex » Mon Jun 03, 2019 11:23 am

hi!

It recently came to my possession a Sharp MZ-80b with MZ-FIO2 & a Custom printer like card.

Unfortunately, a floppy card is missing and I want to connect a floppy to my MZ80b in order to run some CP/M stuff!

As these cards are really rare nowadays I decided to make (clone) a DIY pcb from the schematic [url]http://web.archive.org/web/201509262024 ... 80b_sm.pdf

I would like to ask if someone has a better-scanned service manual or willing to make a hi-res scan of his mz80FI card in order to have it as a guide trying to guess... the low-res printed pins of the service manual.


Thank you in advance
Alex

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

Post by tingo » Wed Jun 05, 2019 2:31 pm

Unfortunately, I don't have a better manual, or a MZ-80b / floppy controller card.
Are you trying to redraw the schematic and do a new PCB layout?
--
Torfinn

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

Post by dat-alex » Thu Jun 06, 2019 5:25 am

Thank you tingo for your reply.
YES! that's exactly what I am trying to do.
MZ80b-FI cards are really rare I think and is the only way I can read/load CP/M on this machine -I think. :)

(With the help of some photos (found from the net) parts placement would be helpful and makes double sided autoroute works better I think.)

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

Post by dat-alex » Thu Aug 15, 2019 10:20 am

Still didn't managed to find an FDD interface card for my 80B.

Do you think that an Sharp MZ1E05 will be in any way compatible with MZ80B-FI Sharp MZ80b-FI ?

I know that MZ80b-FI card has no eprom and uses in-built IPL routines but do you think the rest of hardware will be compatible?

Alex ;)

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

Post by hlide » Thu Aug 15, 2019 10:53 am

MZ-1E05 (MZ-700/800/2000): Mini Floppy Disk Interface / Controller card ( MZ-1F19, MZ-1F02 )

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

Post by tingo » Thu Aug 15, 2019 11:01 am

There are several "layers" of compatibility requirements, like (this is not an exhaustive list):
- mechanical - does the card physically fit into the connector on the machine?
- electrical / signals - does the machine have the signals that the card requires (and vice versa) on the correct pins?
- logical / program - is the machine able to use the card correctly
You would need to check the various manuals, to figure out it that is possible.
Example: if the signals are the same, but the connectors / pinout are different, an adapter can be made.
--
Torfinn

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

Post by dat-alex » Thu Aug 15, 2019 2:13 pm

Hi! Tingo

Thank you for a quick response my friend.

You are asolutely right about ALL you thioughts, Let me 'walk through' one by one to express my opinion on your thoughts:

- mechanical - does the card physically fit into the connector on the machine?
No I think the card does not fit into MZ80B expansion box card holders

- electrical / signals - does the machine have the signals that the card requires (and vice versa) on the correct pins?
Yes I checked all signals are available (question about +5v supply) signal adapter needed

- logical / program - is the machine able to use the card correctly
I think this is the main problem , my friend, of the whole concept
MZ80K , MZ80A, MZ700 etc are using an IPL program already in ROM that on booting first thing is to check $F000 for an FDD eprom booting routines.
SHARP MZ80B (according to manual) uses a different method. IPL only tries to boot from tape or FDD if present (Actually there is a small portion of code that checkes for the presence of FDD interface card and if not present passes control to tape loading.
So I think the main concept is to force MZ80B to load for example from external eprom found on MZ-1E05 external eprom.
OR patch te original onboard eprom with the correct FDD code to access external card!

You would need to check the various manuals, to figure out it that is possible.
I will do so when I find some more spare time!

Example: if the signals are the same, but the connectors / pinout are different, an adapter can be made.
As pinout os different (checked) adapter is needed.

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

Post by tingo » Sun Aug 18, 2019 12:06 pm

Well, then you also need to check the code in the MZ-1E05 eprom, and figure out:
- where in the address map does it live?
- are the routines in there compatible with the MZ80B ROM routines?
So just more work for you, I'm afraid.
--
Torfinn

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

Post by hlide » Sun Aug 18, 2019 7:16 pm


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

Post by dat-alex » Mon Aug 19, 2019 3:01 pm

Thank you both of you! for the infos.

I think this is a a long term project.
I will inform you af any proggress....
;)

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