OK, I know it looks a bit like a cash register, especially when it’s sitting on the disk unit but I like it! I’ve removed all of the internals today and given the cases a good clean inside and out. I’ve secured the FDD and HDD in the working disk unit and made an attempt to get the FDD working.
The FDD is an Epson SMD-400. Like the HDD it has a non-standard connection, with power being supplied via the interface cable as opposed to the usual separate cable. Unlike the HDD it doesn’t work and I’ve been unable to make it read or write to any disks. I’ve had it apart and fiddled a bit with the spin speed and head alignment but no joy. Oddly a cable to nowhere has been soldered to the board, I have no idea what it would have been connected to but hope it’s not something painfully obvious like the head.
The unit does spin up and the head moves around but it fails on every disk I’ve tried. It would of course be nice to slot another drive in there, I’ve got plenty of them but of course they all require a separate power cable.
With no serial cable and no FDD I’m rather limited on what I can do with the machine as I’m unable to get any files on to it. In desperation I opened up my Windows 95 box and trailed the cable from its floppy into the PX-16 disk unit so the Windows 95 box could power it. However with it connected to the floppy interface on the PX-16 the Epson won’t start up.
I gave up and turned my attention to the installed modem. It has an RJ connector that I’ve not seen on a UK modem before. Usually they’re RJll’s with 4 connections. This looks more like an RJ45 and it has 8 connections, although it’s a UK specified machine and the modem is made by a UK company.
I started up Term and sent some modem commands to COM 2 and got the usual OK’s back. I tried to kludge a cable together but was unable to get a dial tone. So a slightly more frustrating day today although I did have fun playing with XTGold which was on the disk I’d salvaged from the Equity, it seems like quite an impressive file manager.
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.
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.
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.
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!
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.
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.
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.
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.
I shall be away for the beginning of this year’s Retrochallenge, so in order to hit the ground running when I get back I thought I’d make sure all my machines were primed and ready for action. To that end I’ve recently sorted out the batteries in my PX-8′s and today my attention turned to my Commodore 128D.
The machine is in pretty good condition, the cassette port is a bit flaky and the built in 1571 drive seems to read and write to disks reasonably successfully. My interest lies in using CP/M on the C128 and I really needed to secure a way of getting data into the machine in this mode.
This has caused me some considerable headaches, in its native or C64 mode the machine uses Group Character Recognition (GCR) to write data to the disks in the 1571. The 1571 is also capable of writing Modified Frequency Modulation (MFM) disks as used by CP/M and under CP/M disks using the following formats can be read:-
With third party software such as Juggler even more formats are supported.
Armed with Big Blue Reader, the original CP/M system disk, a clutch of DSDD disks and my bridge machine running DOS and 22Disk I thought I was well prepared. However no matter which combination of disks and formats I use I cannot successfully format a disk with the 1571 nor the 1581. I’m pretty sure the disks are OK, they seem to work without problems with the Epson TF-20 and PX-8 and the 1581 and 1571 drives appear happy to do everything except format.
More in desperation than hope of success I put one of the disks that I’d formatted with the TF-20 and PX-8 in the C128, typed DIR. To my surprise and excitement the C128 came up with some text at the bottom of the screen reading Epson QX-10. I pressed return and the drive chugged away, thought about it for a while and came back with ‘No file.’ uh, there were definitely files on the disk.
I had a search around and discovered that when the format description comes up at the bottom of the screen you can cycle through different options. So I tried again and using the right arrow key found the next selection was ‘Epson Euro’ I pressed return, the drive chugged away and up popped the disk contents, yipeee!
I loaded PIP quickly just to check it worked, which it did and I then formatted a fresh disk in the TF-20, copied the text adventure Snowball onto it and put it into the C128. On the first attempt I got a BDOS error but on the second attempt it loaded.
So I now have a way of getting software downloaded from the Internet into the C128 in CP/M mode, albeit a somewhat circuitous route via the PX-8 but a way nonetheless.
I currently have the C128 hooked up to an IIyama LCD panel via the s-video port which means I can only run in 40 column mode however I do have a cable that will allow me to connect via Scart and run in 80 column mode which I shall try next as much of the software I’ve tried assumes this mode.
So now hopefully I’ll be able to get on with things as soon as I return, try some CP/M software on the C128, hopefully get it talking to the Epson PX-8 via RS232 and I have some unused 3.5″ DSDD disks on the way which I’m hoping I’ll be able to format successfully with the 1581.
Well here it is, the first installment of Silent Running, a text adventure created using Inform. The initial idea was to create something that would run on my Epson PX-8 which is a CP/M based machine. The first speed bump was locating a Z-machine interpreter for CP/M until it was pointed out to me that as I had the original Zork games for CP/M I had a suitable interpreter.
The Zork games typically came as two files, for instance, Zork1.com and Zork1.dat, the .com file being the interpreter and the .dat file the story file. The interpreter supports version 3 story files and if you create a compatible story file you can rename it Zork1.dat then run Zork1.com and your game will load and run.
Needing to create version 3 story files I opted for Inform 5 as the compiler and was of course free to write the source code in any suitable text editor. Thus development has taken place on a variety of machines including the Atari Portfolio, Epson PX-8, Epson Equity LT and some more modern machines. I had hoped to compile the code on the Equity but I still haven’t had any success.
The game itself is heavily influenced in tone by Snowball from Level 9 which remains my fondest memory of text adventuring, that and Melbourne House’s The Hobbit. I would estimate that I’ve completed about a quarter of what I’d hoped, therefore there are a number of elements within the game that may currently seem like red herrings. The current goal is to achieve access to the biodome area of the freighter.
There will of course be many bugs, not the crash your system type, but responses to player input that are not catered for and the like. Once you’re in the world creating it it’s difficult to jump outside and imagine how others are going to interact with it, reports would be welcome.
I’ve been quite absorbed by this process which has been enjoyable although it has meant I haven’t had as much time to keep up with all the other entries as I’d have liked and I’m looking forward to doing that now.
You’ll need an interpreter should you wish to try the game, you should be able to find one here:-
If like me you need an interpreter for CP/M you can download Zork and the included interpreter here.
No progress on the Silent Running adventure for a couple of days. I got bogged down in trying to resolve a particular issue, realised it was time to walk away and come back fresh which hopefully I’ll do today or tomorrow.
Instead I’ve been messing around with the Equity, trying to understand what it’s capable of. My first experience with a PC as opposed to machines such as the Amiga and Commodore 64 was a Pentium 90 based machine with Windows 3.1, so the pre Pentium days passed me by.
I’ve been trying to compile the code I have written so far with the Equity with no luck as yet. As a point of interest the code compiles on a Core 2 Quad essentially instantaneously. On a Pentium 166 it takes a few seconds. On the Equity it’s taking around 4 minutes before failing on a specific library issue. I need to try the Minform library I mentioned in an earlier post next.
I also wanted to see what games would run on the Equity and found an early version of a Secret of Monkey Island demo which loads and runs. I was never really aware of the limited graphics abilities of the early PC’s having been spoilt by the abilities of the Amiga and its custom chips, it’s pretty basic stuff as I’m discovering.
The Equity has two option slots, one is currently occupied by the hard drive controller card and I believe the only other card produced specifically for the option slots by Epson was a modem card. Somewhat bizarrely one just came up on Ebay, unused, and new in the box so I snapped that up (only bidder) and it’s on its way.
I’ve been trying to settle on one platform for the development of my Retrochallenge Winter Warmup project, a text adventure for my (and other) CP/M based Epson PX-8. Not that long ago I acquired an Epson Equity LT laptop circa 1989.
The unit itself is in remarkable condition cosmetically and runs quite happily when booted into DOS using the internal 3.5″ floppy drive. However when originally attempting to format the internal hard drive the format would progress normally to about cylinder 158 or so whereupon it would slow to a snail’s pace taken roughly 20 minutes per cylinder from thereon.
Given that I don’t really need 20MB of disk space for my project I got the unit out again and used fdisk to create a DOS partition that only used the first 156 cylinders or around 4-5 MB of the drive. The format progressed successfully and I installed MS DOS 3.2 from the original Epson disk that came with the unit.
I have a fondness for Epson design from this era and I think it’s a great looking unit. The screen is pretty good and I like the keyboard. The main specifications are:-
CPU – NEC V30 (μPD70116) CMOS microprocessor, compatible with Intel 8086 runing at the same speed as the 8086 but 10% – 30% faster. (DIP switch on front on unit allows switching between 4.77 & 10mhz speed)
RAM – 640k
Floppy Drive – μPD765A controller supporting four 360Kbyte or 720Kbyte 3.5″ disks.
Hard Disk – JVC JD-3824R RLL type, 21.44 Mbytes 95mm diam.
Option Slots – Two 8bit expansion slots (Modem on the way from US)
Graphics – Built in LCD and RGB output for external monitor CGA standard up to 8 grey levels.