Did you know there were typewriters that used ball point pens to draw not just text but also graphics? I’ve collected several of these over the years. Read on to discover a world that you didn’t know existed.
Category Archives: Retroputing
Another Commodore 64 Black Screen Repair
(This was originally a Twitter thread on September 23, 2018)
September 23, 2018
On the bench today is a Commodore 64 picked up from @Recta_Pete at Atari Party East 2018. This revision is the cost reduced long board because of the sparse components around the VIC-II. I already spot several problems.
Commodore 64 Black Screen Repair
(This was originally a Twitter thread from September 26, 2018)
September 26, 2018
Next on the bench is an early #c64, 1982 original motherboard with 5 pin video out and a lovely ceramic VIC-II. These tend to be tricky in my experience.
Recapping an Epson HX-20 Slabtop
(This was originally a Twitter thread from March 24, 2020)
March 24, 2020
The Epson HX-20 is on the bench for some TLC like a new battery, new capacitors, cassette tape belt, and possibly more. Maybe I’ll eventually dial a BBS with it.
Recapping the Apple PowerBook 160 LCD Display
(This was originally a Twitter thread from May 26, 2022)
May 26, 2022
Today I’m going to recap the LCD display on this PowerBook 160. It has a passive matrix LCD display capable of displaying 4-bit grayscale (16 shades of gray). The display was dim before with some severe artifacts (after adjusting the contrast slider) but now it will only show a black screen.
@mac84tv has an excellent page that lists the capacitors needed for this recap along with the links to Mouser to purchase.
Recap and repair of a Mac Classic II
(This was originally a thread posted on Twitter on June 30, 2022)
June 30, 2022
On the bench for recapping today is a Mac Classic II, the last of the b&w compact Macs (1991). I forgot how small the motherboard was.
MJB Cartridge Expander and 80 column card for C64
I’ve had this cartridge expander for a few years and always assumed it was commonly known about and that the ROM inside had been dumped. It seems that may not be the case, so this page is to provide the information I have about it.
Getting Programs For The C64 CP/M Cartridge
The Commodore 64 CP/M cartridge was released sometime in the early 1980’s, shortly after the introduction of the C64 itself. The cartridge contained the necessary Z80 chip inside to run CP/M software natively. While a novel idea, it was a bit too late with the popularity of CP/M waning which itself had been released almost a decade earlier. To make matters worse, it seems to only work on very early revisions of the Commodore 64. I personally am only able to get it to work reliably on a Rev A motherboard (1982, with no s-video output).
The Jameco JE520 Voice Synthesizer
The latest acquisition is the JE520 by Jameco. This external voice synthesizer came in two variants: the JE520-CM for Commodore and JE520-AP for Apple II. The only difference was the interface connection to the computer. The Commodore version, the one I have, connects to the user port while the Apple II version connects via an interface slot card. Otherwise, I believe the rest of the hardware to be the same. I found an advertisement for it in RUN issue 7 1984— it retailed for $115-$150.
Commodore 1520 Plots .SVG Images
I’ve put together a quick program that can convert an .SVG file into data statements that can be used to plot it on a Commodore 1520 Printer/Plotter. The program doesn’t run on the Commodore 64 (yet) but instead runs in the browser. It’s not ready to release yet as it’s fair picky about the types of .SVG files you feed it.
To whet your appetite, I’ve prepared a .D64 disk image that has four BASIC programs that will plot four different Commodore logos.
And if you need plotter pens for your Commodore 1520 printer, you can get new old-stock pens from @futurewas8bit!