Uploaded March 2025 | Updated September 2026, 2 weeks ago
People make fun of the ZX81/Time Sinclair 1000. It was a super cheap computer which had some questionable corners cut. Let's see if these three machines work, fix them if they don't and then see if these computers are worthy of praise or live up to their bad expectations.
0:00 What is the ZX81?
10:05 Testing and repair
44:36 Composite mod
53:46 Let's play some games
1:04:33 Final issue and conclusion
-- Links
ZX81 Wikipedia:
en.wikipedia.org/wiki/ZX81
Schematics:
retroisle.com/sinclair/zx81/Technical/Hardware/ZX81-Schematics.php
researchgate.net/profile/Edoardo-Dotto-2/publication/352756710/figure/fig10/AS:1038793201164290@1624679007435/Electrical-diagram-of-the-Sinclair-ZX81-detail.ppm
Composite Mod:
https://blog.codesurfer.dev/zx81-timex-sinclair-1000-composite-video-mod/
github.com/redhawk668/ZX81-Composite
Oregonian Issue: (With pricing)
archive.org/details/computer-83-special-section-the-oregonian-june-16-1983/page/n1/mode/2up
Keyboard membrane:
zxrenew.co.uk/Sinclair-ZX81-Membrane-p102352920
ULA Replacement:
tindie.com/products/charlieingley/vla81-zx81-ula-replacement
Adrian's Digital Basement Merch store:
my-store-c82bd2-2.creator-spring.com
Adrian's Digital Basement ][ (Second Channel)
youtube.com/channel/UCbtwi4wK1YXd9AyV_4UcE6g
Support the channel on Patreon:
patreon.com/adriansdigitalbasement
My GitHub repository:
github.com/misterblack1?tab=repositories
-- Tools
Deoxit D5:
amzn.to/2VvOKy1
store.caig.com/s.nl/it.A/id.1602/.f
O-Ring Pick Set: (I use these to lift chips off boards)
amzn.to/3a9x54J
Elenco Electronics LP-560 Logic Probe:
amzn.to/2VrT5lW
Hakko FR301 Desoldering Iron:
amzn.to/2ye6xC0
Rigol DS1054Z Four Channel Oscilloscope:
rigolna.com/products/digital-oscilloscopes/1000z
Head Worn Magnifying Goggles / Dual Lens Flip-In Head Magnifier:
amzn.to/3adRbuy
TL866II Plus Chip Tester and EPROM Programmer: (The MiniPro)
amzn.to/2wG4tlP
aliexpress.com/item/33000308958.html
TS100 Soldering Iron:
amzn.to/2K36dJ5
ebay.com/itm/TS100-65W-MINI-Digital-OLED-Programmable-Soldering-Iron-Anti-static-Structure/113382669853
EEVBlog 121GW Multimeter:
eevblog.com/product/121gw
DSLogic Basic Logic Analyzer:
amzn.to/2RDSDQw
ebay.com/itm/USB-Logic-DSLogic-Basic-Analyzer-16Ch-100MHz-4Ch-400MHz-Xilinx-Spartan-6-FPGA/202543965672
Magnetic Screw Holder:
amzn.to/3b8LOhG
harborfreight.com/4-inch-magnetic-parts-tray-90566.html
Universal ZIP sockets: (clones, used on my ZIF-64 test machine)
ebay.com/itm/14-16-18-20-24-28-32-40-pin-IC-Test-Universal-ZIF-Socket-Fs/303206721971
RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI)
retrotink.com
Plato (Clone) Side Cutters: (Order Five)
ebay.com/itm/1-2-5-10PCS-Micro-Scissor-125mm-PLATO-170-Electronics-Cutter-Side-Cutting-Pliers/163458746184
Heat Sinks:
aliexpress.com/item/32537183709.html
Little squeezy bottles: (available elsewhere too)
amzn.to/3b8LOOI
--- Instructional videos
My video on chip removal without damage:
youtube.com/watch?v=XQVjwPsVFd8
--- Music
Intro music and other tracks by:
Nathan Divino
@itsnathandivino
People make fun of the ZX81/Time Sinclair 1000. It was a super cheap computer which had some questionable corners cut. Let's see if these three machines work, fix them if they don't and then see if these computers are worthy of praise or live up to their bad expectations.
0:00 What is the ZX81?
10:05 Testing and repair
44:36 Composite mod
53:46 Let's play some games
1:04:33 Final issue and conclusion
-- Links
ZX81 Wikipedia:
en.wikipedia.org/wiki/ZX81
Schematics:
retroisle.com/sinclair/zx81/Technical/Hardware/ZX81-Schematics.php
researchgate.net/profile/Edoardo-Dotto-2/publication/352756710/figure/fig10/AS:1038793201164290@1624679007435/Electrical-diagram-of-the-Sinclair-ZX81-detail.ppm
Composite Mod:
https://blog.codesurfer.dev/zx81-timex-sinclair-1000-composite-video-mod/
github.com/redhawk668/ZX81-Composite
Oregonian Issue: (With pricing)
archive.org/details/computer-83-special-section-the-oregonian-june-16-1983/page/n1/mode/2up
Keyboard membrane:
zxrenew.co.uk/Sinclair-ZX81-Membrane-p102352920
ULA Replacement:
tindie.com/products/charlieingley/vla81-zx81-ula-replacement
Adrian's Digital Basement Merch store:
my-store-c82bd2-2.creator-spring.com
Adrian's Digital Basement ][ (Second Channel)
youtube.com/channel/UCbtwi4wK1YXd9AyV_4UcE6g
Support the channel on Patreon:
patreon.com/adriansdigitalbasement
My GitHub repository:
github.com/misterblack1?tab=repositories
-- Tools
Deoxit D5:
amzn.to/2VvOKy1
store.caig.com/s.nl/it.A/id.1602/.f
O-Ring Pick Set: (I use these to lift chips off boards)
amzn.to/3a9x54J
Elenco Electronics LP-560 Logic Probe:
amzn.to/2VrT5lW
Hakko FR301 Desoldering Iron:
amzn.to/2ye6xC0
Rigol DS1054Z Four Channel Oscilloscope:
rigolna.com/products/digital-oscilloscopes/1000z
Head Worn Magnifying Goggles / Dual Lens Flip-In Head Magnifier:
amzn.to/3adRbuy
TL866II Plus Chip Tester and EPROM Programmer: (The MiniPro)
amzn.to/2wG4tlP
aliexpress.com/item/33000308958.html
TS100 Soldering Iron:
amzn.to/2K36dJ5
ebay.com/itm/TS100-65W-MINI-Digital-OLED-Programmable-Soldering-Iron-Anti-static-Structure/113382669853
EEVBlog 121GW Multimeter:
eevblog.com/product/121gw
DSLogic Basic Logic Analyzer:
amzn.to/2RDSDQw
ebay.com/itm/USB-Logic-DSLogic-Basic-Analyzer-16Ch-100MHz-4Ch-400MHz-Xilinx-Spartan-6-FPGA/202543965672
Magnetic Screw Holder:
amzn.to/3b8LOhG
harborfreight.com/4-inch-magnetic-parts-tray-90566.html
Universal ZIP sockets: (clones, used on my ZIF-64 test machine)
ebay.com/itm/14-16-18-20-24-28-32-40-pin-IC-Test-Universal-ZIF-Socket-Fs/303206721971
RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI)
retrotink.com
Plato (Clone) Side Cutters: (Order Five)
ebay.com/itm/1-2-5-10PCS-Micro-Scissor-125mm-PLATO-170-Electronics-Cutter-Side-Cutting-Pliers/163458746184
Heat Sinks:
aliexpress.com/item/32537183709.html
Little squeezy bottles: (available elsewhere too)
amzn.to/3b8LOOI
--- Instructional videos
My video on chip removal without damage:
youtube.com/watch?v=XQVjwPsVFd8
--- Music
Intro music and other tracks by:
Nathan Divino
@itsnathandivino
