Re: General Thoughts and Questions on Lisa

Hi Tom,

concerning your questions:
> 1. Is a Lisa 2 worth less than a Lisa 1 that has been upgraded to
> Lisa 2?
Simply: Yes!
> 2. As far as I know, the only differences between the 1 and the 2
> are: different ROMs, a cut resistor? somewhere, twiggy drives, a
> LisaLite card, and the front faceplate. Can anyone verify this? And
> is there any way that I could find some of these parts to downgrade
> my upgraded Lisa 1 back to its original condition?
These are the main differences, but not all. The main-board is also different; the CPU-board, too. Lisa's mainboard is the small board, which contains the I/O plugs on the reverse of the Lisa. One of the ways to check, whether you have an upgraded Lisa 1 or a Lisa 2 is to check the parts manufacturer date. Mostly following numbers are printed onto soldered parts of boards. For example you can read 4001 and 8239 (sometimes 3982) then you are provided with the data, that it's a chip named 4001, which was manufactured in the year 82 in week 39
> 3. I was wondering this today, and this might be totally off track,
> but I'll put it out there. Would there be any way to design an
> interface that would allow a Lisa to use a Disk ][ drive and think
> it was a Twiggy? I have no idea if this would work or not, but I
> just thought I'd mention the idea. Imagine if someone could get
> this to work though, with a supply of Lisa 1 faceplates it might be
> possible to (almost) recreate Lisa 1s.
Yes, thats possible, but a huge effort. Perhaps Patrick Schaefer could help you with some hints...
There is a seller / collector in Canada, who sells Lisa 1 plates and is also member in this LisaList. If I remember right, he wants roundabout 5000$ for the faceplate...
> 4. Following the previous question, I know that the disk ][ drives
> were designed so you would put a disk in and close the little door
> in front, then it would start reading. I've never seen a Twiggy
> work in person; does it "suck" disks in like a 400k drive? Is there
> an auto-eject mechanism?
The floppy disks were stuck in and the eject-mechanism stopped the disk. There was no front-door. But there was an eject-button above the slot. You push it and the write/read head was pulled away from the disks surface and the disk was released. Totally mechanical. No auto-eject. Not at that time.
> 5. Could a regular 5.25" disk be modified in such a way that it
> would work like a Twiggy disk?
You need a lot of time to re-engineer such a drive. But there are three persons, who did some work, which could be useful. Patrick Schaefer was the first, who did this
James MacPhail from Sigma Seven Systems did the same approx a year later at that time I was in contact with a japanese person with the nickname "momo chan", who did the same

But perhaps there are some more people outside, feel free to tell us about your efforts!

greetings: Tom from Bavaria, the country of the famous Octoberfest, the marvellous castles of Koenig Ludwig and the Alps

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