MicroPath P1

[RWAP]

The wife of Ian Gledhill (Mutant Caterpillar) has posted on Facebook about a new find she made in a local shop - called a MicroPath P1, it appears to be a custom ZX81 complete with custom ROM and keyboard, plus an add-on, specifically aimed at the Homeopathy specialist.

Pictures below. Has anyone ever come across anything linked to this?

[RWAP]

Ian has got it working now and dumped the 12 ROMs (the one in the ZX81 plus 11 in the expansion board) !!

[PokeMon]

Is this kind of medical database ?

[Lardo Boffin]

Is this kind of medical database ?

I'm not sure I would use homeopathy and medical in the same sentence but I suspect so!

It certainly looks like you can search for symptoms and 'cures' but I didn't realise the zeddy could do floating point maths to a high enough degree to calculate the dilutions used in this branch of 'medicine'.

Having a whole load of presumably pageable ROMs is quite cool though!

[RWAP]

The ROMs are obfuscated - Brendan Alford has decoded all of the ROMs too now.... (Attached)

[RetroTechie]

I suppose this is one of those custom applications with low # of users which must have been fairly common for the ZX81. Just not many surviving beyond their intended use. A ROM add-on + matching sticker over the keyboard, not that special from a technical p.o.v. really. Nice find though!

Curved pcb traces +1. And single sided too!

Looking at that pcb: back in the day there existed some kind of sticker sheets with pieces of pcb traces (for various widths), holes spaced 0.1" apart to easily use for IC footprints, pin headers etc. With a soft pencil you'd rub those off onto a design sheet or even a bare pcb for prototyping uses (which I did quite a few times). Designs you'd get look a lot like what's seen here.

Chances are someone used this method to transfer such symbols onto a transparent sheet (= photo mask). A time-consuming manual job... Then for each product: UV light + photosensitive pcb, developer, etching, followed by a chemical tin bath. With low numbers, may easily have been done manually, quite possibly in-house somewhere.

The ROMs are obfuscated (..)

Perhaps to simplify pcb layout?

[crashtestolly]

Hi, I was 13 when my dad Peter Chappell (hence the P, he was very self important) made 400 of these. I helped modify them and put those plastic binders on the manual pages, and fitted bigger heat sinks, stuck on the overlays etc.
I have no time for homeopathy but still play with computers raspberry pis now. I was given a zx80 which effectively set my career from that day!
If you look Peter up online you can see the craziness that followed. I just inherited the first P1. (He died last week). If you want to know more post here or try ollyporders at gee mail dot com as this is the first forum I have ever joined nd may forget to check back.
I will try to get mine running again but it was great to see those screen shots thanks. They brought back memories.

[crashtestolly]

[msknight]

I'm not sure I would use homeopathy and medical in the same sentence but I suspect so!

The forum really needs an "upvote" button IMHO. That had me laughing hard.

[1024MAK]

Hi, I was 13 when my dad Peter Chappell (hence the P, he was very self important) made 400 of these.

Hello and welcome to our forum crashtestolly!



Thank you very much for posting

Mark