MZ Collection - Home made hardware (card)

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TMst
Posts: 8
Joined: Fri May 31, 2019 2:35 pm

MZ Collection - Home made hardware (card)

Post by TMst »

Hi,

As mentioned on Facebook I'd like to share some information, pictures, documents etc. regarding my MZ collection that I am still checking myself. Hope to receive some feedback, help and advise what to do with it (trade, sell, or if something is useless - throw it in a bin ;) )

First topic is a card that was inserted in the expansion slot of one of my MZ-800 computers. Based on the connection on the back of the card it appeared to be a QD interface (the QD drive cable fits).
If you compare it to an MZ-1E19 it is a lot smaller though, doesn't have the same chips and doesn't need the extension piece. If it is connected the cable is pushed a centimetre into the MZ-800.
After turning on the MZ-800 the card didn't do anything. The selection Q - Quick Disk is not available from the menu. Cleaned the card with WD40 and IPA (connection was dirty - see pic) but that didn't do a thing.

The card doesn't seem to be created by professionals. It has Dutch text on it so my first impression was that it might have been created by hobbyists (maybe a usergroup?) in the Netherlands.
See pics below.
P5310039.JPG
P5310038.JPG
P5310037.JPG
P5310036.JPG
Last edited by TMst on Sat Jun 08, 2019 7:10 pm, edited 1 time in total.
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Pacman
Posts: 171
Joined: Mon Feb 05, 2018 2:59 pm

Re: MZ Collection

Post by Pacman »

Hi,

The electronic board is more like an 8-bit output data buffer (74LS244) associated with address decoding (74LS00 and 74LS02).
There is no EPROM so no software to work.
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TMst
Posts: 8
Joined: Fri May 31, 2019 2:35 pm

Re: MZ Collection

Post by TMst »

OK - interesting :) Any idea what the practical use of it could be?
Connection is exactly the same as the QD drive so that was my first guess.
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fitus
Posts: 59
Joined: Tue Jun 12, 2018 8:52 pm

Re: MZ Collection

Post by fitus »

Some kind of ROM disk, probably?
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Pacman
Posts: 171
Joined: Mon Feb 05, 2018 2:59 pm

Re: MZ Collection

Post by Pacman »

To know it would require detailed photos of the double-sided circuit to see what address is used by this card.
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Pacman
Posts: 171
Joined: Mon Feb 05, 2018 2:59 pm

Re: MZ Collection

Post by Pacman »

Is the left electronic board of the first picture (the green PCB) the QD interface?
It looks like it has exactly the same components: LS00, LS02 and LS244.
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TMst
Posts: 8
Joined: Fri May 31, 2019 2:35 pm

Re: MZ Collection

Post by TMst »

Yes, the left board is the QD interface. Made this picture to show the difference and similarities between the two. The 'home-made' board has the following components.
74LS244N A + TT4LS00B1 + T74LS0201
If these are indeed the same I assume it is a home-made / hobbyist QD interface - but not working correctly.
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