Last Updated on 3. October 2026 by Link status: OKSuffocation
Here comes the circuit board, the one that all Link status: OKSergey Kiselev Projects connect. The backplane consists of 7x 8-bit ISA slots, an ATX connector, two LEDs and a power button. Other than that, it doesn't have much more to offer apart from forming a real 8088 PC from all the 8-bit ISA cards.
Link to the project
Link status: OKLink to the project
Series contributions
Link status: BrokenISA 8-bit 8088 Board – Das Hauptprozessor Board mit 8088 oder V20
Link status: OKISA 8-bit Backplane – Platine mit ISA Steckplätzen für die gebauten ISA Karten
Link status: BrokenISA 8-Bit Super VGA Card – Karte basiert auf Trident TVGA9000i Chip
Link status: OKISA 8-bit Ethernet Card – Moderne Netzwerkkarte basierend auf dem Realtek 8019 Chip
Views
Facts
- 7x 8-bit ISA slots
- Power LED / Activity LED
- Power button
- 20-pin ATX connector
- Pin header for power LED and button
- -5V voltage regulator to generate -5V from ATX power supply's -12V
Circuit diagrams
Documentation
Keine zusätlich Dokumentation vorhanden alle Infos gibts auf GitHub – Link status: OKLink to the project.
Assembly
Record
| Description | Worth |
|---|---|
| Gerber available | Yes |
| Gerber file | Link status: OKLink |
| Ordered where | JLCPCB |
| Piece | 5 |
| Price including tax and delivery | 25€ |
| Special features | Leedfree, Blue |
Here are the Gerber files saved. Please check the original site for anything newer.
Components
I ordered the components from various retailers. The price for one unit was around €20.
| Reference | Component type / Value | Quantity | Description | (approx.) Price in € | Check |
|---|---|---|---|---|---|
| ISA 8-Bit Backplane | 1 | I ordered mine from JLCPCB | £5.00 | ||
| U1 | 74HCT74 | 1 | Integrated Circuit (IC): DIP-14 Package Mouser 595-SN74AHCT74N | 0.60 EUR | |
| U2 | 74HCT14 | 1 | Integrated Circuit (IC): DIP-14 Package Mouser 595-SN74AHCT14N | 0.60 EUR | |
| U3 | LM7905C | 1 | Integrated Circuit (IC): -5V Voltage Regulator Mouser 512-LM7905CT | 0.50 EUR | |
| U1, U2 | DIP-14 | 2 | IC Socket: 300 mil socket Mouser 517-4814-3000-CP | 0.40 EUR | |
| D1 | 3 mm LED, blue | 1 | LED display Mouser 696-SSL-LX3054USBD | 0.30 EUR | x |
| D2 | 3 mm LED, two-colour red/green | 1 | LED display Mouser 696-SSL-LX3054IGW | 0.40 EUR | x |
| D3, D4 | 1N4148 | 2 | Diode Mouser 512-1N4148 | 0.20 EUR | x |
| SW1 | 6 mm | 1 | Short-stroke push button: Short-stroke push button, straight Mouser 653-B3F-1000 | 0.30 EUR | |
| Page 1 | ATX | 1 | Connector: 20-Pin power connector Mouser 538-46015-2006 | 0.80 EUR | |
| P2, P3 | Pen holder | 2 | Connector: 4-pin, 2.54 mm pitch Mouser 649-68002-104HLF | 0.20 EUR | |
| BUS1-BUS7 | ISA slot | 7 | Connector: 62-pin card edge connector, 2.54 mm pitch Mouser 571-6-5530843-5 | 3.80 euros | |
| C1 – C19 | 10 µF | 19 | Capacitor: 16V, MLCC, 5 mm pitch Mouser 810-FG28X5R1E106MR06 | £1.20 | |
| C20 | 1 µF | 1 | Capacitor: MLCC, 5 mm pitch Mouser 810-FG28X5R1H105KRT0 | 0.20 EUR | |
| C21, C22 | 0.1 µF | 2 | Capacitor: MLCC, 5 mm pitch Mouser 594-K104K15X7RF53H5 | 0.20 EUR | |
| R1, R2 | 10 kOhm, wired | 2 | Resistance Mouser 291-10K-RC | 0.30 EUR | x |
| R3 | 1 kOhm, wirewound | 1 | Resistance Mouser 291-1K-RC | 0.30 EUR | x |
| R4 – R7 | 470 Ohm, wirewound | 4 | Resistance Mouser 291-470-RC | 0.30 EUR | x |
| RR1 – RR5 | Resistor network: do not populate (Optional, should not be populated.) | 0.00 EUR | – | ||
| Total material costs (guideline value) | 17.00 EUR |
Structure
Variations
Recommended logic family CMOS 74HCT series
- Possible alternatives: 74AHCT or 74ACT
- TTL-ICs (74LS, 74ALS, 74F) work but consume more power.
LEDs
- Power LED (D1): Recommended 3mm blue LED; 5mm or other colours also work
- Activity LED (D2): recommended 3 mm red/green bi-colour LED with two connections (antiparallelly connected LED crystals)
Capacitors
- Recommended: Ceramic multilayer capacitors with 5 mm pitch
- 2.5 mm pitch or axial capacitors can be adapted by bending the leads
- Electrolytic or tantalum capacitors for C1–C19 (10 µF) are possible — Observe polarity!
Order
The instructions on Github were more detailed than I would have written them, so I've translated them, changed the order slightly, and reproduced them here. Link status: OKThis way to the original.
- Check circuit board for visible defects (scratches, short circuits)
- Clean PCB with alcohol
- Solder components from low to high
- Solder diodes D3 and D4 in place — Consider polarity (Black ring = marking)
- Solder resistors R1–R7
- Voltage regulator U3 shape and solder in — hole for heatsink must align with PCB hole
- Solder capacitors C1–C22 — Consider polarity, falls polarised
- Solder in DIP sockets U1 and U2 — Observe alignment
- Solder LEDs D1 and D2 Note polarity at D1
- Solder pin headers P2–P3
- Solder switch SW1
- Solder ATX power connector P1
- Solder ISA card connectors BUS1–BUS7
- Carefully check all solder joints; re-solder if necessary.
- Optional: Check for short circuits and supply voltages with a multimeter
- Clean the board thoroughly with alcohol, wipes, and a toothbrush
- Carefully insert ICs into the sockets — align pins on a hard, non-static surface if necessary
- Check the orientation of the ICs; ensure no pins are bent
- Re-inspect finished circuit board
- Install Micro-8088-Board and other ISA cards, connect power supply
- Turn on, test, install software — and have fun!
Commissioning
You can supply power to the backplane, and you should do so before plugging in a card, but otherwise, it can't do much itself. It's more of a link.
Miscellaneous
Data sheets
7474
Source: Link status: Unknownhttps://www.alldatasheet.com/view.jsp?Searchword=7474
7414
Source: Link status: Unknownhttps://www.alldatasheet.com/datasheet-pdf/pdf/27375/TI/7414.html
General Tips
Soldering points
Lötstellen gerade an den IC’s nochmal genau, am besten mit dem Microskop oder Lupe, auf Kurzschlüsse und Kontakt prüfen. Durchmessen mit Multifunktionsmeter bzw. Durchgangsprüfer.
For small solder joints on through-hole components, use flux if possible; it makes life easier and increases the quality of the connection.
Problems
Conclusion
| Description | Worth |
|---|---|
| Successful | Yes |
| Price per piece | ~20€ |
| Soldering time | 1 hour |
| Function | Gut |
| Is it worth it | Yes, a nice addition to the set |
| Restrictions | 8-bit, no additional functionality |
Related Posts
- Link status: OKRetro Projekt – DiskBuddy 64
- Link status: OKRetro Projekt – Joystick Tester
- Link status: OKRetro Projekt – Voltage Blaster
- Link status: OKRetro Projekt – 8Bit Isa Ethernet Card (isa8_eth)
- Link status: OKRetro Projekt – FDC USB Floppy Disk Controller
- Link status: OKRetro Projekt – Floppy Disk Controller (isa-fdc)
- Link status: OKRetro Projekt – ROMOS
- Link status: OKRetro Projekt – USB auf RS232 Mouse Adapter
- Link status: OKRetro Projekt – Monotech ISA Double ROM
- Link status: OKRetro Projekt – greaseweazle 4.1
Sources
To the project
Link status: OKGitHub Link
Link status: OKParts list
Link status: OKGerber files
Retro pages
Link status: OKhttps://archive.org – Alte Software, Magazine, Handbücher und viele mehr.
Link status: Unknownhttps://theretroweb.com – PC Hardwareverzeichnis.
Link status: OKhttps://www.winhistory.de/index.php – Dos, Windows Versions Beschreibungen.
http://www.win31.de/links.htm – Win 3.1x Tools und Tricks
Retro Forensics
Link status: OKhttps://forum.classic-computing.de/forum – Deutsch/Englische Formum mit vielen Retro-Computer Enthusiasten.
Link status: OKhttps://www.vogons.org – Hier habe ich schon viele Tips zu Hardware gefunden, sie haben auch eine Treiber Verzeichnis.
Link status: OKhttps://www.dosforum.de – Forum mit strikten Regeln und sehr hilfreich in Bezug zu DOS, Windows fragen werden nicht gerne gesehen.
Link status: OKhttps://dosreloaded.de – Dos, Hardware Repartur, Bios Dateien und mehr.
Link status: OKhttps://www.winhistory-forum.net DOS and Windows history.
Retro Shops
Link status: OKhttps://ram-co-shop.de – PC Teile auch neuere, schon viel dort bestellt hat immer funktioniert.
Link status: OKhttp://www.amoretro.de – Verkauft auf EBay und hat ein nettes Verzeichnis alter Hadware
Link status: OKhttps://retroreiz.de – Atari, Nintendo, Seaga und anderes.
Link status: Brokenhttps://www.retroworld.info/de – Aufkleber, Schilder und mehr.
Link status: OKhttps://retesa-nb.de – Alte Hardware rund um den PC
Link status: Unknownhttps://www.retro8bitshop.com – C64 lastig
Logbook
| Date | Change | Author |
|---|---|---|
| 03.10.2026 | Logbuch-Tabelle auf Log-Liste umgestellt | Suffocation |
| 09.09.2025 | Boards arrived | Suffocation |
| 30.08.2025 | Post created and PCB ordered. | Suffocation |
| 21.06.2025 | Soldered the board, unfortunately I'm missing the 20-pin ATX connector. I only have a 24-pin one that I could shorten, but I'd rather wait until the ordered one arrives. | Suffocation |
| 20.06.2025 | Gathered stuff Post created | Suffocation |