Restoring a HX-20

The HX-20 is a small computer released by Epson in 1982, produced until ~1987[2]. It has a small built in dot 
matrix printer and my one has a removable audio microcassette module. It can run programs in BASIC. 
I got it at a flea market with no cables and doubt that it would be restorable. (It also came with me after that 
to a food market, a tea shop, a caf, a shelter kitchen, a bar, a church, then a 2000s night at a club. it had a 
busy day.)

When I first plugged it in there was no response, so I inspected the batteries and found that they were corroded. 
After cutting connecting wires and removing them, the device was responsive when powering it directly. It beeped, 
and text was juuust about visible on the screen- almost invisible unless looking at it from a very shallow angle. 
Moving the 'viewing angle' dial on the side improved this minimally, as did supplying it with a higher voltage. 

Being from 1982, the manual[1] assumes a vastly different understanding of computers compared to other manuals 
I've read. It goes into a bizarre amount of detail into nowadays intuitive concepts like 'scrolling', which was 
wonderful to read. It also has such characterful cartoon illustrations that are lacking in any manual I've read.

After reinitialising the device and having some problems with we managed to get it to (sometimes) print. However, 
it did not like this much and would often crash ('charge battery').
I suspect this may be fixable by replacing some of the caps...
It was also out of ink so we tried using India pen ink; in the process we crumbled one of the foam rollers- we 
used some packaging foam to fashion a new one. This worked, but only the first half of a line gets inked so we 
should try a different ink.

Programming in BASIC? Using the Cassette machine?
As far as I can tell, the cassette machine is exclusively used for saving programs (which won't stop me from 
trying to listen to them with my microcassette machine). I don't know how easy it'll be to get any interesting 
sounds out but I'll try.

I think first I'll try writing some simple Adventure style text based mini game:
10 L=0
20 P=0

30 PRINT "YOU ARE IN A DARK LABORATORY"
40 PRINT "THERE IS A LASER, A POWER SUPPLY AND A VACUUM CHAMBER"
50 INPUT "WHAT DO YOU INTERACT WITH"; A$

60 IF A$="LASER" THEN GOTO 100
70 IF A$="POWER SUPPLY" THEN GOTO 200
80 IF A$="VACUUM CHAMBER" THEN GOTO 300

90 PRINT "I DON'T UNDERSTAND"
95 GOTO 50

100 PRINT "THE ROOM GLOWS RED AS A BRIGHT BEAMS FLOOD THE VACUUM CHAMBER"
110 L=1
120 GOTO 30

200 PRINT "A WHIRRING SOUND EMANATES FROM THE SUPPLY AS COILS ON THE TABLE CONJURE UP MAGNETIC FIELDS"
210 P=1
220 GOTO 30

300 IF L=1 AND P=1 THEN GOTO 400
310 PRINT "A MACHINE SITS EMPTY ON THE TABLE; SURROUNDED BY COILS AND OPTICS"
320 GOTO 30

400 PRINT "A MACHINE SITS ON THE TABLE; SURROUNDED BY COILS AND OPTICS. A CLOUD OF ATOMS INSIDE GLOWS, SUSPENDED 
INSIDE A GLASS CELL"
410 GOTO 30


Other HX20 links:
[1] Manuals: https://files.support.epson.com/pdf/hx20__/hx20__u1.pdf
https://archive.org/details/hx20-basic/mode/2up
[2] https://www.vintage-calculators.nl/page91.html
https://oldcrap.org/wp-content/uploads/2023/04/epson-hx20-tips-tricks.pdf
https://www.treblig.org/refurb/epson-hx20.html
https://electrickery.nl/comp/hx20/Julian_Wald/index.html