First post, by Zalog
So thought it was probably time to start a thread on my current little project.....
The origins of this one go back a fair way so best start at the beginning. Back when I was a teen I was fascinated by the Amstrad Mega-PC they had on display at the Model shop in Gloucester, it was very cool and played all the games I wanted, plus it would be great for word processing. After much nagging my dad did get a PC, however it wasn’t a mega-pc much to my disappointment. I did get to have a go on one however as a friend of mine was given a Mega-PC Plus (yes the 486 version did exist !) as a Christmas present and I occasionally got to play with it when I visited – the mix of megadrive and basic 486 games was pretty cool – unfortunately he threw it away for a Pentium a few years later ☹.
So the Mega-PC always stuck in my memory – after doing a bit of research, about 8 years ago when I came across one with its monitor (rare!) keyboard, joystick and gamepad, that had been stored in in a shed, I brought it for the princely sun of £40. But that said the base unit was a state, it was covered in mud, the motherboard had suffered a battery leak and damaged the HDD controller and the 3.5” floppy drive had been replaced with a standard unit by cutting into the face plate (ouch!), also some idiot had cut the integrated monitor power cable in half ! Still with some careful cleaning and a repair to the power cable – amazingly it worked – abet without a HDD on the PC side due to the battery leak. After playing on the Mega-drive side for a couple of years and using the PC via the floppy as a word processor for locoscript (!), life eventually got in the way and it was stored safely away. Moving up to the present, recently my daughter started doing A level computer science at school, so I fished out the Mega-PC as a demonstrator system– rather than let her take apart my modern system for a look see.
This got me thinking, could I get it fully working again….. Well a quick search on the internet told me the motherboard could be replaced and as a plus I could in effect get a Mega-PC plus – and thus a plan was hatched and I waited 6 months for a 7486SLC to pop up. Due to Covid and people having time to clean their attics, one popped up recently that I was able to get hold of. It was missing its HDD and a few other strange things (such as the video ram oddity which I’ll talk about another day…..) – but they are as rare as Hen’s teeth these days, so despite these things, as it ran I brought it.
After looking at the faceplate of the 7486, I realised that I didn’t have the skill to transplant the 7486 drive cover into the missing bit on the Mega-PC faceplate and thus I decided as it wasn’t going to be a museum piece, I might as well go on the upgrade warpath and do some upgrades with some of the kit I have in store. So far the motherboard is in, the clock chip replaced with an Alt12887 and I’ve fitted a Gotek into the floppy bay (see photo) !
The current upgrade plan is:
Fitted – 786SLC Motherboard, replaced Dallas Clockchip with Alt12887, Gotek Flash Floppy
Awaiting to add - Cyrix FasMath CX-83S87-33-JP Co-processor (who knows I may need it 😊 ), 16MB RAM, Quantum LPS 400MB HDD (Master), CF IDE Adaptor (Slave), Soundblaster AWE64 (for now as I have it to hand – will hopefully replace it with Keropi‘s special soundcard for the Mega-PC when its ready). A heatsink to add to the CPU (as it gets hot playing DOOM !), and perhaps a suitable flatscreen.....