With a long background in developing for the Z80 based SAM Coupe computer it was due to several suggestions that I started to bring my knowledge to developing for the RC2014, so thanks to David who asked if I could make an interface to allow RC2014 peripherals to connect to the SAM, and Shiela who asked if my SAM Coupe SID Soundchip Interface happened to work with the RC2014! Thanks to them I'm now enjoying developing for a new, but familiar, platform! If there's any peripheral you'd like to see for the RC2014 drop me a suggestion!

To keep up to date with new developments please see my social media accounts on X (Twitter), Mastodon and BlueSky. Also keep a look out there for when I'll next be exhibiting at retro computing events around the UK - since 2022 I've been exhibiting at the Centre for Computing History in Cambridge, the Retro Computer Museum in Leicester and various other smaller shows.

Any questions or comments please use this contact form on my main website.

Scroll down to see the released interfaces or use these quick links:

- *NEW* SAA1099P Soundchip Interface (Released June 2025)
- SID Soundchip Interface (Released June 2020)
- Graphics OLED Interface (Released July 2020)
- ZX True Tone (ZXTT) (Released September 2021)

For ordering there are PayPal Buy buttons in the product information for each interface, for payment using PayPal or Credit/Debit cards. To combine shipping for several items or for more than quantities of one please send me a message via my contact form for a combined total.

The SAA1099P can considered to be very similar to using two AY sound chips, although with a few changes such as stereo volume controls. It offers 6 sound generators, each can then select from 8 octaves and 256 tones per octave (giving a frequency range of 31Hz to 7.81KHz). Two noise generators and two envelope controllers. Each channel has separate volume settings for left and right volume so stereo effects and panning are easily achieved.

Like my other interfaces the I/O port can be selected with jumpers to select the port used to avoid clashes with other hardware you have, as well as using multiple cards of the same type in your system to increase the number of sound channels. The soundchip is socketed and tested, with an 8MHz oscillator fitted to drive it at the correct frequency. A standard 3.5mm stereo socket is provided for the audio output.

Optional Extra

If you're interested in computer audio I've added the option to include issue 11 of "SAM Revival" magazine - the magazine I produce specifically for the quirky, British SAM Coupe computer! This issue was originally released back in 2004, but in 2024 for exhibiting at the 'Synthesized' show at the Centre for Computing History in Cambridge (UK) I revamped the issue giving it a brand new full colour layout, updated some of the articles and had the issue professionally printed. The whole issue is focused on sound on the SAM looking at software and hardware, plus it's bundled with a 19 track audio CD with a selection of music from the SAM Coupe showcasing the SAA1099P soundchip and additional sound hardware.

This interface connects to a standard RC2014 slot and allows the Z80 to write to the registers of the SID chip. To assist timing I've also added an interrupt generator which can be set to generate approximately 50/60/100Hz interrupts (timed to match the frame rate of the Commodore 64). There are jumpers on the interface to allow the base I/O address to be configured, with the default set to 0x54.

The sound output is via a stereo 3.5mm socket on the side of the interface into which you would then connect an amplified speaker. With the SID output being mono the same signal is fed to both the left and right channels.

Since the initial launch in June 2020 I've revised the PCB for the SID soundchip interface; adding silk screen markings for the type of SID it's configured for and adding a power LED indicator to the board. Currently shipping are the latest V1.2 revision from 2024 as shown in the image above. (The videos below will show earlier revisions).

Please note that the interface is supplied without a SID soundchip - you'll have to fit your own SID chip. As there are two types of SID (6581 - from the original C64, and the 8580 from the redesigned new-look C64C) the interface has to be built up specifically for the chip that is going to be fitted due to different supply voltages and filter capacitors. When purchasing below please select the type of chip you would like the interface configured for.

(01/11/20 Update!) I've now released an adapter to allow a 8580 SID to be connected to hardware designed for the 6581 so I can provide a solution to allow you to use either SID type with this interface. I've added an option in the Buy Now drop down menu for the SID Interface configured for the 6581 plus the 8580 Adapter module bundled in with it. (Also available separately here: 8580.samcoupe.com)

The interface also supports modern SID replacements, I've used the SwinSID, SwinSID Ultimate and the ARMSID myself. These operate independantly of the power circuitry and filter capacitors and the likes of the SwinSID Ultimate and ARMSID can be configured by software as to what chip type they are emulating, as well as advanced filter settings in the case of the ARMSID.

Currently, there's no specific software for the RC2014 to drive the interface, so please don't purchase the interface and think you'll be playing SID music within seconds! Programming information with regards to how to write to the SID's registers and enabling the interrupt controller is covered in the guide with the interface along with some Z80 routines and listing for using the SID in Microsoft BASIC. There is Z80 code on github (as originally written for the Z80 based SAM Coupe) for emulating the C64's 6510 CPU to play .sid files, someone could rise to the challenge of porting that to the RC2014!

As software appears for the interface I'll link it, or have it downloadable, from the resources section below, along with links to anything else that's interesting.

Please select from the drop down menu the shipping area (UK, EU + European countries, or Rest of World*) and click 'Buy Now' for checkout through PayPal (either using your PayPal account or as a guest for payment by credit/debit cards.)

Please also select in the drop down options if you wish the interface to be configured for the 6581 or 8580 SID chip, or if you wish the 6581 version with the 8580 SID Adapter included to allow the interface to use both types.

I decided to go the OLED route rather than LCD as there are some nice very benefits. There's no backlight or contrast issues. More importantly, instant transition of pixels from off to on and vice versa, rather than the often very slow (and too blurry for animation) response time you generally find with small LCD modules.

A graphic module also gives far more scope in terms of possiblities and uses than an alphanumeric display. A simple text display using it can be easily achieved with a little bit of coding. I'm finishing off some routines for this, see the media section below for an image with my current text display code.

The user guide I've written explains how to initialise and write to the display, with Z80 source code examples. As just mentioned, I'm working on routines for easy text printing which I'll add to the download section below when ready.

Test assembly code for displaying text. Using a 6x8 pixel font gives 4 rows of 21 characters on the display, with the font (for ASCII characters 0x20 to 0x7F) taking up 576 bytes.

- Bitmap display (@zoggins on Twitter)
- Dino Runner WIP (@shieladixon on Twitter)

- Quazar OLED for RC2014 Test
   (NCOT Technology on YouTube)
- [Part 1] Quazar Graphic OLED - RC2014 Real Bitmap Display - Overview and Mini Review
   (NCOT Technology on YouTube)
- [Part 2] Quazar Graphic OLED - Retro Programming in C and Z80 Assembly on the RC2014
   (NCOT Technology on YouTube)
- Github Code source for the above two videos
   (NCOT Technology - @NCoT_Tech on X/Twitter)

- Tunnel game tweet and blog post by @shieladixon on X/Twitter

- Versatile font routines being coded by @jskists on X/Twitter

The ZXTT is an add-on module for Ed Brindley's YM / AY soundcard for the RC2014 DIY computer (and compatibles) and its purpose is to give it the exact clock frequency to the soundchip to have the correct pitch matching the AY-3-8912 that was fitted in the ZX Spectrum 128K onwards.

The tone of the YM and AY soundcards are all derived from the clock signal it receives. The ZX Spectrum's AY soundchip was fed with a 1.7734MHz clock, which this module matches. There isn't much control of the clock on Ed's soundcard, as his circuit can provide a clock from either the main system clock divided by 2 or divided by 4, or on the Rev 6.1 card a separate oscillator module. If you are using the card to play ZX Spectrum tunes and the AY is fed a clock speed lower then the pitch of the tones will be lower, likewise if clocked higher then the pitch of the tone will be higher, so the tunes won't sound exactly right. The wrong frequency can also affect the envelope effects.

My ZXTT module replaces one of the chips on the YM/AY interface and feeds the soundchip the exact 1.7734MHz clock speed so the tunes will be the exact same pitch as the ZX Spectrum. Essential for any serious ZX Spectrum demotune fans out there!

This module will fit both the Revision 5 of the YM/AY Soundcard boards (the version currently sold as a kit by RFC2795 Ltd here on Tindie - see their listing for YM2149 Sound Card for the RC2014) and Revision 6.1 boards (gerbers/schematics for both 5 and 6.1 are available from Ed himself on Github -> electrified/rc2014-ym2149)