Category Computers

More PX-16 Adventures

Retrocosm 2 Comments

Things are progressing quickly with the PX-16.  Having got the main unit working my attention was today turned to the two disk units that came with the Epson.  Designed to hold either one or two FDD’s or an FDD and an HDD the units sit under and clip onto the main machine.  The two units are then connected via a cable at the back.

JVC JD-3824

The first unit I tried seemed dead, no amount of fiddling would coax it into life.  The second unit however powered up first time, although the FDD in it won’t currently read or write to any disks.  The dead unit had a daughter card and from it a cable with a 26 pin connector which I assumed was for the HDD, although I’d not seen that sort of connector before.

Epson Equity

I enquired over at the Vintage Computer Forums as to whether anyone recognised this connector.  Mike S & Chuck G pointed me in the direction of the JVC JD-3824 drive, Chuck remembering it from a Gridlite he used to own.  I did a search for JVC JD-3824 and had a doh! moment when my own blog came up.  This is the drive in my Epson Equity.  I was considering, somewhat reluctantly, taking the Equity apart and trying the HDD in the PX-16.

26 Pin Connector

Then I remembered I had another Equity, seriously beaten up and not working, tucked away somewhere.  I dug it out, took it apart and low and behold there was a JVC JD-3824 drive in it and on the drive that familiar 26 pin connector and cable, I love moments like that!

JVC JD-3824 in the PX-16

I quickly removed the drive, cleaned it up and put it in the PX-16 drive unit into which I’d also installed the daughter card from the dead unit.  I turned it on and… nothing.  Then I noticed a jumper by the mainboard connector to the daughter card.  On checking the unit from which I’d removed the daughter card I realised the jumper was in the alternative position.

PX-16 & Disk Unit

I swapped the jumper, turned the unit on and the HDD whirred into life.  Not only that but it actually booted to the drive’s original installation of MS-DOS.  I was astonished to say the least, it’s noisy and clunky but I love it.

PX-16 Mainboard with ROM Sockets (Right) & Modem (Left)

The PX-16 is highly configurable, in fact it’s so highly configurable that it makes my head hurt.  There’s a bank of DIP switches in the unit to set depending on which configuration you require.  This includes two boot modes, one of which behaves like a regular PC but also denies access to the system’s ROM’s.  I’m still trying to fully understand the other mode.

I’d like to try and get the FDD working next and I want to build an RS232 cable at some point.  The system also came with some additional RAM which I can’t seem to access in the PC boot mode although it’s available in the standard mode so I need to look at that.

Additional RAM

There’s also a Modem in the unit which I’d like to try and I need to do some swapping around to get all the working components into the cleanest cases and secure the various drives properly.

Epson PX-16 Throws A Googly

Retrocosm 2 Comments

It’s looking as though this Retrochallenge is going to end up considerably less focused than the last.  Not helped by a late start due to a family holiday I’ve now been thrown a googly by the arrival of a new machine.

For some time I’ve lusted after an Epson PX-16 and with one recently listed on Ebay it was an opportunity not to be missed.  Listed as non-working but including some additional bits such as a spare screen and disk unit I felt confident I’d be able to resurrect it so I put in a bid.  Somewhat amusingly for me, not so much the seller I got it for 99 pence.

It’s in good condition cosmetically and I’ve put it on charge hopeful that I’ll be able to get it working tomorrow.  Information on the PX-16 is pretty scarce, as usual for old Epson stuff the best resource is Fred Kraan’s excellent site.

 

I shall try and find out some more information and take some better pictures in due course.  For now I know this machine runs MS-DOS 3.2 from ROM and has an 8088 compatible V20 processor.  In the picture above the PX-16 is sitting on top of the optional disk unit which can house two floppy drives or a floppy drive and hard disk.

Remembering Gary Kildall

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(Gary Kildall 1942 - 1994)

With Retrochallenge well underway I again find myself deep in the world of CP/M, it therefore seems appropriate to mark the 17th anniversary of the untimely passing of Gary Kildall, its creator.  Much has been written about Gary Kildall and much of it seems contradictory or distorted by vested interests.

With varying stories surrounding both his death and his dealings with IBM, and as someone who only knows of Kildall through coming late to his work it seems appropriate to pull together some resources from others who knew Gary and have written eloquently about him.

Gary Kildall worked as a co-host with Stewart Cheifet on the Computer Chronicles nearly all of which can be accessed here:- Computer Chronicles.  There is an edition dedicated to the memory of Kildall here:- Computer Chronicles – Gary Kildall

Stewart Cheifet was interviewed by Earl Evans on the Retrobits Podcast and spoke at length about Gary, you can find it here:- Retrobits – Stewart Cheifet

A detailed account of Kildall’s work and his dealings with IBM and Microsoft can be found here:- The Gary Kildall Legacy

There’s a fairly recent article here entitled:- The Man Who Could Have Been Bill Gates

A moving Eulogy from Tom Rolander here:- Gary Kildall Eulogy

And lots more info and pictures on the same site:- Digital Research

What is clear to me is that Gary was liked by all who met him and that the personal computer industry as a whole owes him a great debt of gratitude for his enormous contribution.

More on Kildall and CP/M can of course be found on Wikipedia.