Many a computer from the 1980s is today yellowed and brittle. The plastics age considerably over the decades. You can do some mitigation by retrobrighting with hydrogen peroxide. However for some machines you can even get replacement cases, and in some cases even brand new key caps for the keyboard. Today we will transform a beige Commodore A500 into a black beauty!
on that note: i just booted up an A500 that I bought 20 years ago for the first time
i never had bothered with the machine because I preferred its older brother A1000 for the case design and overall style
as it turns out, the previous owner installed a 2MB RAM + clock upgrade, as well as an internal HDD in this A500! i had no idea they were capable of having internal HDDs D:
i soldered a new clock battery in, and it's running like new. pretty amazing machine for its footprint.
Today's lunchtime hack was the Hilbert curve on the #penplotter, which was fun to write (I needed an explicit stack because BASIC only has global variables). I really love the flickering lights. #retrocomputing
New blog post! If you're setting up a BlueSCSI image for your classic Mac, there's lots of little tricks and traps for the first-timer. I'm hoping this entry will make things easier, and you'll also learn how to change your hard drive icon... in Japanese. #retrocomputing#mac68k#bluescsi
As a youngster, I made my first Deluxe Paint pixel art on an Amiga 1000 in 1986. Coming from a Commodore 64 with a fixed palette of 16 colors, the Amiga was revolutionary at the time.
I went on to use "DPaint" professionally on a daily basis for around 10 years, creating pixel graphics for games, advertising agencies and television shows.
I am astounded at how advanced a game Elite was on the BBC Micro. This video does a great exploration of the mechanics of it, how it was written, the history around it, and its influences to this day. He also gave a big shout out to others who have thoroughly documented the game as well. #RetroComputing#RetroGaming#ComputerHistory Elite: "The game that couldn't be written"
Data Digger for Windows 95 is a program that can open certain corrupted files, allowing you to dig through them and extract the text you need. You must set the system date to 1996 before using it, or it will refuse to open.
Matthias Wiesmann reflects on how much computing used to be diverse over four decades ago. As an example he explains how weird the Commodore 64 was compared with modern systems.
I cannot date this, but apparently some time in the distant past (possibly 80’s?) the International Harvester tractor company used punch cards for inventory and parts ordering. #retrocomputing#farming
Hate those fake updates from USPS where their computer sees that nothing has happened for a couple of days and inserts some generic "oh, we've totally put it on a truck and it's heading to you!” It has been sitting there for 3 days! Definitely not arriving today. 😔
Grouped what I think is +5V regulation on secondary side. With my extremely limited understanding, seems anode side of opto D8 is managed by HA17431 IC8. If +5V voltage falls then opto turns on and asks for more juice. Too high or just right opto is off. But how is over current handled? Could IC8 be bad and that's causing the power supply to go into over current mode?
Doing some searching about how a diode in reverse can be used as a voltage regulator leads me to Zener diodes. Looking at D22-D26, D26 has a black stripe while the rest all have green stripes. D26 must be a zener diode.
If I lift D26, will that prevent the +5V rail from coming up? Will something else on the power supply blow up without it?
Remembered I had a big variac. I was able to get the power supply to start by slowly bringing up the AC voltage. It’s hard to repeat, but I was able to do it more than once.