2 layers100 × 77.5 mm
2 layers100 × 77.5 mm
SmartDiskII
btb/SmartDiskII60An hybrid Disk ][ and SmartPort controller
- Size
- 100 × 77.5 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 42
- Nets
- 125
- Pads
- 380
- Tracks, vias
- 759, 59
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 7 (file 20221018)
- Created
- 22 Jul 2023
- Updated
- 28 Jan 2024
Overview
SmartDiskII is an open-source printed circuit board by btb, from the btb/SmartDiskII repository on GitHub, published under the Apache-2.0 licence. It is a 2-layer board of 100 × 77.5 mm with 42 parts on 125 nets, routed with 759 tracks and 59 vias.
It is built around the 74LS245SC, 27C256-17/J and 74LS174DC, with the 74LS00SC, 74LS05P-E and 74LS132P-E among its other parts. Its parts include 14 ICs, 13 capacitors, 5 resistors, 3 connectors and 1 diode.
Main components
1174LS245SC
-0℃~+70℃ 12ns@5V,45pF 15mA 24mA 4.75V~5.25V 74LS 8 Bidirectional Output enable Schmitt trigger Tri-State - Buffers, Drivers, Receivers, Transceivers ROHSTexas InstrumentsBuffers, Drivers, Receivers, Transceivers27C256-17/J
-0℃~+70℃ 256Kbit 4.5V~5.5V EPROM Parallel Port (Parallel) - Non-Volatile Memory (ROM)Microchip TechnologyNon-Volatile Memory (ROM)
74LS174DC
-0ns 0℃~+70℃ 1 16mA 20ns 30MHz 30ns@5V,15pF 4.75V~5.25V 400uA 6 74LS Series 8mA Asynchronous Push-Pull Reset Rising Edge - Flip Flops ROHSonsemiFlip Flops
74LS00SC
-0℃~+70℃ 15ns@5V,50pF 2 2.7V 2V 4 4.75V~5.25V 400uA 500mV 74LS 800mV 8mA NAND Gate - Logic Gates ROHSTexas InstrumentsLogic Gates74LS05P-E
-- Inverters ROHSRenesas ElectronicsLogic Gates
74LS132P-E
DIP-14-20℃~+75℃ 2 2.7V 22ns@5V,15pF 4 4.75V~5.25V 400uA 500mV 74LS 8mA NAND Gate Schmitt trigger DIP-14 Logic Gates ROHSRenesas ElectronicsLogic Gates74LS20P-E
DIP-14-20℃~+75℃ 15ns@5V,15pF 2 2.7V 2V 4 4.75V~5.25V 400mV、500mV 400uA 74LS 800mV 8mA NAND Gate DIP-14 Logic Gates ROHSRenesas ElectronicsLogic Gates74LS21PC
DIP-140℃~+70℃ 18ns@5V,50pF 2 2.7V~3.4V 2V 4 4.75V~5.25V 400uA 500mV 74LS 800mV 8mA AND Gate DIP-14 Logic Gates ROHSonsemiLogic Gates74LS30PC
PDIP-140℃~+70℃ 1 1.1mA 18ns@5V,50pF、20ns@5V,50pF 2.7V 2V 4.75V~5.25V 400uA 500mV 74LS Series 8 800mV 8mA NAND Gate PDIP-14 Logic GatesTexas InstrumentsLogic Gates
74LS323PC
DIP-200℃~+70℃ 29ns@5V,15pF 35MHz 4.75V~5.25V 8 Output enable、Asynchronous parallel load function、Supports forward and reverse shift Tri-State DIP-20 Shift RegistersTexas InstrumentsShift Registers
NE556
SOP-140℃~+70℃ 2 200mA 4.5V~16V 5mA SOP-14 555 Timers / Counters ROHSGRTimers / Counters
README
README.mdSmartDiskII
The SmartDiskII is basically an Apple "Liron" disk controller with the IWM chip replaced by the discrete components from the Disk II controller, which the IWM was originally based on, and using firmware (i.e. SoftSP) which has been appropriately modified to use those components instead of the IWM.
SmartPort Operation
Because the SoftSP firmware (as of v6) is slot-dependent, a different copy is required for each slot the card may be used in. The slot 1 version is in the 1xxx region of the EPROM, slot 2 version is at 2xxx, etc. A set of latches (U9) is used to automatically select the appropriate region depending on which slot the SmartDiskII is placed in.
Disk II Operation (experimental)
The card is designed to also work as a regular Disk II controller, though results can be inconsistent depending on the components used. Failures of this system can lead to corrupted floppy disks.
For this reason it is recommended to use true TTL ICs for all of the logic chips. In addition, for the chip at U5, Apple's original Disk II controller design called for a 9334 rather than a 74LS259. Indeed, using a 9334 does appear to make the circuit more tolerant of these issues.
5.25 Floppy operation works by having the Disk II boot rom in the 0xxx region of the EPROM, and therefore active while U9 is held in reset. Plugging a floppy drive into the DRV1 connector should automatically activate the correct firmware because of the presence of +5V on pin 12, but because some devices do not have that pin connected, you can also close jumper JP8 to force the card into Disk II boot mode.
Configuration
U8 is the standard 16-sector Disk II state machine data, P6, on a 2716-compatible EPROM.
U11 is a special combination of the Disk II boot ROM and the SoftSP firmware, SmartDiskII.bin.
Parts
42| Qty | Value | Footprint | References |
|---|---|---|---|
| 11 | 100n | Capacitor_THT:C_Disc_D4.3mm_W1.9mm_P5.00mm | C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13 |
| 3 | 3.3K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R2, R3, R5 |
| 2 | 22u | Capacitor_THT:CP_Radial_D5.0mm_P2.50mm | C1, C2 |
| 2 | 74LS174 | Package_DIP:DIP-16_W7.62mm | U1, U9 |
| 2 | ~ | Jumper:SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mm | JP2, JP3 |
| 1 | 1M | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R1 |
| 1 | 2758/16/32 P6 | Package_DIP:DIP-24_W15.24mm | U8 |
| 1 | 2758A/B | Jumper:SolderJumper-3_P1.3mm_Bridged12_RoundedPad1.0x1.5mm_NumberLabels | JP4 |
| 1 | 27C256 | Package_DIP:DIP-28_W15.24mm | U11 |
| 1 | 4148 | Diode_THT:D_DO-35_SOD27_P7.62mm_Horizontal | D1 |
| 1 | 47K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R4 |
| 1 | 74LS00 | Package_DIP:DIP-14_W7.62mm | U14 |
| 1 | 74LS05 | Package_DIP:DIP-14_W7.62mm | U3 |
| 1 | 74LS132 | Package_DIP:DIP-14_W7.62mm | U4 |
| 1 | 74LS20 | Package_DIP:DIP-14_W7.62mm | U6 |
| 1 | 74LS21 | Package_DIP:DIP-14_W7.62mm | U7 |
| 1 | 74LS245 | Package_DIP:DIP-20_W7.62mm | U12 |
| 1 | 74LS259/9334 | Package_DIP:DIP-16_W7.62mm | U5 |
| 1 | 74LS30 | Package_DIP:DIP-14_W7.62mm | U10 |
| 1 | 74LS323 | Package_DIP:DIP-20_W7.62mm | U13 |
| 1 | Apple II Expansion Slot | Apple2:Apple II Expansion Edge Connector | J1 |
| 1 | DRV 1/SP | MyConnector:PinHeader_2x10_P2.54mm_Vertical_Shrouded | J2 |
| 1 | DRV 2 | MyConnector:PinHeader_2x10_P2.54mm_Vertical_Shrouded | J3 |
| 1 | DiskII Mode | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | JP8 |
| 1 | NE556 | Package_DIP:DIP-14_W7.62mm | U2 |
| 1 | ~ | Jumper:SolderJumper-2_P1.3mm_Bridged_RoundedPad1.0x1.5mm | JP5 |
| 1 | ~ | Jumper:SolderJumper-3_P1.3mm_Bridged12_RoundedPad1.0x1.5mm_NumberLabels | JP1 |
Questions
How big is the SmartDiskII PCB?
It measures 100 × 77.5 mm and has 2 copper layers, 1.6 mm thick.
What parts does the SmartDiskII use?
42 parts, built around the 74LS245SC, 27C256-17/J, 74LS174DC and 74LS00SC. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the SmartDiskII KiCad files?
From the btb/SmartDiskII repository on GitHub, at the commit this page was made from: the board is SmartDiskII.kicad_pcb and its schematic SmartDiskII.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the SmartDiskII design in my own project?
Its repository publishes it under the Apache-2.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
Similar boards
- 2 layers100 × 77.5 mm
- 2 layers113.8 × 82.4 mm
TK2000 DiskInterface REDUX
frubem/TK2000_DiskInterface_REDUX
Forked from https://codeberg.org/hkzlab/TK2000_DiskInterface_REDUX
42 partsCC-BY-SA-4.0 - 2 layers65.1 × 92.8 mm
TK2000 InterfaceDeDrive
clemarfolly/Microdigital-TK2000
Reprodução da PCB do TK-2000 da Microdigital, clone do Micro-Professor MPF-II
18 parts17 - 2 layers476.5 × 299.5 mm
- 4 layers236.8 × 240.9 mm
DIY Video
jimbro1000/DIY-Video
General purpose video system for 8-bit computers using 74LS logic
315 parts1 - 2 layers
Rogelio Pineda 2;12 AM AMLDC-2044B
ForgottenMachines/Entrex
The technologies documented here will include all like-kind systems manufactured by Nixdorf, Redifon, ROCC & Mera, all originally designed by Entrex Inc, Burlington, MA USA.
321 parts1 - 2 layers325 × 209 mm
