Oh my! ✨🦄🌈😎🌈🦄✨ #zxspectrum

ZX Spectrum with illuminated rainbow keyboard

Oh my oh my! 😍 #zxspectrum

Relaxing to some #classical music.

Blondie album Eat to the Beat on a record player

I love Saturday mornings.

Two ZX Spectrum conputers with separate screens and microdrives attached. one is showing a catalogue of files, the other is displaying a BASIC code listing.

ZX Spectrum +3 Disk B

The ZX Spectrum +3 (and Amstrad CPC) “Disk B” expansion port is the same form factor as a 34-pin edge-connector for a 5.25" floppy disk drive that you’d find in an old PC, so we can use those cables without any other interfaces, and just a small modification.

The source for most of this information was Guide on how to connect a 3.5" drive to a CPC6128/664, and my thanks to kokkiklhs on the Spectrum Computing forums for their highly detailed post that got me up and running! After I published this post initially, Guesser reccommended another method for modifying the cable that better protects the Spectrum from damage.

As the CPCWiki article notes, such floppy drive ribbon cables don’t seem to be made any longer but they still come up for sale regularly on eBay (etc.). I’m not really familiar with PCs but the cables tend to come in 3- and 5-connector varieties, and usually with the distinctive twist at one end. The connectors will be a mixture of 5.25" type (i.e. card style connector) and 3.5" type (i.e. 34 pin socket). One edge of the ribbon will usually be marked in red, to signify pin one.

Connecting and configuring

For use with a Spectrum we need a cable with at least one of each type of connector with no twist in between.

In addition, if the cable has at least two of the 3.5" style connectors that’s handy—we can use the extra socket to add a 1N4148 signal diode short pins 33 and 34 together. This that asserts “drive ready” signal when for Disk B when that drive is selected. This isn’t needed for a Gotek since it does provide the Ready signal, but will probably be needed if you are using a real floppy drive from a PC.

Modern PC floppy drives do not provide a drive ready signal which the Spectrum requires. The diode is used to hold the Spectrum's READY line low whenever the external drive is selected. This is better than simply shorting the line to ground as it still allows the the system to detect that the internal drive is empty and therefore doesn't cause the +3 Loader to hang if there is no disk in drive A:. In other words, you can still load tapes from the menu loader without having to remove the cable or manually toggle a switch.

From External floppy drive cable for the Spectrum +3 by Guesser

Diode inserted between pins 12 (anode) 34 (cathode)

(For a more robust solution see that article for instructions on how to solder the diode in line with the cable).

Optionally, shorting pins 11 and 12 will allow the external drive to be treated as the primary drive (i.e. Disk A). In order to have the Spectrum swap the drives (so the extrnal one is considered to be Disk A) then a (non-trivial) internal modification is necessary.

The 5.25" card-edge connector is keyed so it can only be inserted one way up. This is connected directly to the Spectrum’s Disk B expansion port. The keying is reversed so effectively it’s upside down: 

ZX Spectrum +3 with floppy cable inserted

To account for the reversed keying, the floppy drive (in this case I’m using a Gotek floppy drive emulator) connector is fitted upside down. That is, the red stripe (usually pin 1) is actually oriented to pin 34. The locating notch points upwards. I’ve marked mine with “top” as a reminder.

The actual orientation will depend on how the PCB is mounted in your floppy drive (or Gotek). With the drive powered on, but the Spectrum powered off, the drive will complain that the cable “may be upside down” but once the Spectrum is powered on the drive will work correctly.

The Gotek jumper S1 should be set. All others (M0, S0 etc.) should be un-set. 

Gotek connector with jumper S1 set

Many of the disk images in ZXDB will work directly from the Gotek, but only if the drive has been designated the role of Disk A. To do that, we need to could short pins 11 and 12 but it is a much better idea to perform the internal switch instead. Once that’s done, the Spectrum will treat the Gotek as Disk A (and it seems Disk B as well); the internal drive will be ignored.

ZX Spectrum +3 with Gotek attached

Home made disks

A lot of commercial disk images, though available for download, will have copy protection that will make them difficult to transfer from Gotek to a real floppy. (This is discussed in much more detail in kokkiklhs' thread). They will run fine from the Gotek though.

On the other hand, 2015’s Castlevania: Spectral Interlude by SaNchez et al is available in +3 disk format. Similarly the 2019 game Redshift by World XXI Soft has an unprotected +3 disk image available. (Redshift is available to buy on cassette as well).

Using John Elliott’s DU54 I was able to write each game to either side of a real 3" floppy no problem. Castlevania has a really well implemented save-game system that automatically records your progress on the disk.

3-inch floppy disk with hand-drawn Castlevania logo

Seall! Tha mo bhean air an telebhisean!

Lauren Mhoireasdan, Leas-cheannard Àrd-Sgoiltean Thiriodh is an Òbain

An Easter treat! It’s time for payback… COSMIC PAYBACK!

ZX Spectrum game Cosmic Payback on cassette tape

My stepper motor is giving me grief. This looks like a job for… DISK DOCTOR! 💾🩺🦸🏽‍♀️

partially disassembled ZX Spectrum +33" format floppy disk labelled “Disk Doctor”

How it stared/ how it’s going/ etc. #zxspectrum #fixerupper #16k

closeup of damaged electrical circuitsloading screen for HUNGRY HORACE

Been fixing this, a Dixons branded cassette recorder from ‘83. Very slightly older than I am, and I’ve had it almost that long. Still loading Spectrum games as reliably as it did three decades ago!

disassembled cassette recorder showing exposed electronicsclose up detail, date stamp reads 7-83-21

I’m taking a break from Microdrive refurbishment to catch up with latest news from January 1988. Just running off a quick copy of Outlet magazine while I put the kettle on. #tea #zxspectrum #alphacom32

ZX Spectrum printing out on an Alphacom 32 and a long ream of thermal printer paper

Friday night re-felting my carts. #FF #FeltingFriday #zxspectrum #microdrive #microlife

ZX Spectrum Microdrive cartridges with replaced felt pads

Networkin’ like it’s 1983! Well sort of. But I finally found a legitimate use for the telly’s picture-in-picture mode #zxspectrum #interface1 #sinclair #network #baudrate #chunteyfield

Ah, okay… now it’s #Christmas.

screenshot of Sega Saturn game Christmas NiGHTS

New High Score: 24,180 ☃️

high score table: top place FD RECORDS with 24180

Competition is heating up in round two of the Spectrum Computing Christmas High Score Challenge! This week’s game is The Snowman. spectrumcomputing.co.uk/forums/vi…

ZX Spectrum screenshot, title screen of The Snowman by Quicksilva from 1983

Merry Crashmas! 🌈 🤖 👻 🐢

christmas tree decorated with 1980s toys and a 2020 copy of Crash magazine

Tonight’s silly project: replacing a tired old ZX Spectrum cassette with a freshly-recorded new one! TZXDuino! Sony TCM-818! By far the hardest part was printing a new label!

a tangle of wires, cassette tapes, recorders and ZX SpectrumsUCHI MATA JUDO game on cassette tape with a worn label, and a brand new green cassette with no labeloriginal cassette case and inlay card with new cassette featuring a printed label

Oidhche Shamhna 👻 #spooky

spooky house on a spooky hill with a spooky moon behind some spooky clouds lighting a big spooky tree

Wayhey, it’s new game Saturday: Millie & Molly on Commodore 64!

Commodore 64 cassette tape game Millie ans Molly with illustrated cover showing the main characters.

Morning sun in Connel

Feàrnach

Resistance is… ~futile~ approximately 18KΩ

New project time! It’s a recreated Romantic Robot Multiface 128. (Or rather it soon will be, hopefully!)

ProjectSPECCY recreated Romantic Robot Multiface 128

Pakket overhandigd door de verzender aan de Pickup parcelshop! 🚚 🌈 📦 #zxspectrum #bytedelight