π¬π§ Sinclair ZX Spectrum & Interface 1: Part 1 (First look & test)
31Chapter marks and then full description below ...
00:25 ... "40 Best Machine Code Routines for the ZX Spectrum" Kickstarter book
01:10 ... first look at the keyboard & case
05:00 ... opening it up
11:05 ... ZX Interface 1
11:20 ... AC power supply
12:30 ... removing keyboard from case
17:00 ... "The ZX Spectrum ULA" book
21:15 ... different ULA versions
22:38 ... nice thank-you card from St. Wilfrid's Hospice (refer earlier rambling about a Spectrum+)
24:10 ... back to the Speccy board
25:00 ... composite video mod. starts
29:00 ... RF modulator can is removed from board
31:20 ... composite mod. completed
32:33 ... first power-on test
33:20 ... testing with a keyboard (TS1500)
36:30 ... checking heat with thermal imager
38:30 ... replacing 7805 linear regulator
39:10 ... board closeup
41:40 ... opening up the ZX Interface 1
I don't think I've ever done a video on an original/genuine Sinclair ZX Spectrum ... I've got a Spectrum +2, a Timex Sinclair TS2068 and loads of Soviet/post-Soviet clones, but this is my first genuine 48KByte Speccy. This one is an Issue 2 board.
{Updated as per @1337Shockwav3's comment, thanks}
I thought it might be a little more interesting to look at one that came in an after-market case by Fuller ... the "Fuller Desktop System" or FDS. In this, ahem, "case" it has been modified on the back to accomodate the ZX Interface 1 expansion.
{Corrected as per @markevans2294's comment, thanks}
It also comes with a "ZX Interface 1" that provides MicroDrive, RS232 serial and "ZX network" interfaces.
I'm planning to replace the original ULA (6C001E-6) with vRetroDesign's vLA82 with RGB output, so to test if the machine is working I did the simple composite modification ... well, I stripped out the contents of the RF modulator can and installed a 100Β΅F electrolytic capacitor.
And it seems to be working. I used the keyboard for a TS1500 to test it a little further (the case & keyboard were still drying from their beauty treatments).
I replaced the 7805 linear regulator with a PSU2-5 from EZSBC.
To be continued.
Relevant links (not sponsored):
"40 Best Machine Code Routines" book:
https://www.hueygames.com/40-bmcr-zx-spectrum
Tynemouth Software's always excellent repair blog (Dave):
http://blog.tynemouthsoftware.co.uk/2023/08/zx-spectrum-issue-2-future-proofing.html
Composite modification:
https://spectrumforeveryone.com/technical/composite-mod-for-the-48k-range/
vRetro for replacement ULAs & other goodies (Charlie):
https://www.vretrodesign.com
EzSBC for replacement regulators (Daniel):
https://www.ezsbc.com