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2 layers135 × 97.8 mmNCL501, the printed circuit board in 3D

NCL501

roberto314/NCL501-SCSI-8-Bit6

Recreation of a bootable ISA 8-Bit SCSI Card.

Full screenGitHub.kicad_pcb
Size
135 × 97.8 mm
Copper layers
2
Thickness
1.6 mm
Parts
42
Nets
129
Pads
459
Tracks, vias
1,377, 70
Pours
2
Routed
Yes
KiCad
KiCad 7 (file 20221018)
Created
10 Apr 2024
Updated
14 May 2024

Overview

NCL501 is an open-source printed circuit board by roberto314, from the roberto314/NCL501-SCSI-8-Bit repository on GitHub. It is a 2-layer board of 135 × 97.8 mm with 42 parts on 129 nets, routed with 1,377 tracks and 70 vias.

It is built around the PAL16L8-5JC, 74LS125DC and 74LS245SC, with the 27C128-15, 74LS14PC and 74LS175PC among its other parts. Its parts include 14 capacitors, 11 ICs, 4 connectors and 1 resistor.

Main components

7

README

README.md

NCL501-SCSI-8-Bit

Recreation of a bootable ISA 8-Bit SCSI Card.

There is one PAL on the Card (PAL16L8), it is protected unfortunately. A dump has been done and the equations have been recreated. They might be wrong. BIOS EPROM is a 27C64 Type, RAM is not poplated but a 6116 might be used (24-pin Socket).

Schematic

The new card looks like this:

or the real thing:

Changes are:

  • active termination or passive Termination possible.
  • Term Power with Jumper
  • DB25 Connector instead of DB37
  • smaller (97.75 x 135mm)

For active Termination the following Parts are needed:

text
- C12: 470p Footprint 1206

- C13, C14: 100n Footprint 1206

- U11: MIC5219 2.85V Regulator SOT-23-5

This Adapter has some serious shortcomings:

In my Computer (micro8088) it ONLY works with DRQ/DACK 3, ROM @ D8000 and IO @ 330! IRQ doesn't matter also the RAM onboard is not necessary.

I tested the following Images:

Heads and Sectors working:

spf = sectors/fat, spc = sectors/cluster

  • C: 79 / H:8 / S:32 10 MB (FAT12) works

  • C: 95 / H:8 / S:32 12 MB (FAT12) works

  • C: 39 / H:16 / S:32 10 MB works

  • C: 22 / H:15 / S:63 10 MB doesn't work (non-system disk)

  • C: 21 / H:16 / S:62 10 MB doesn't work (non-system disk)

  • C: 21 / H:16 / S:63 10 MB doesn't work (non-system disk)

  • C: 63 / H:16 / S:32 16 MB (FAT12) works

  • C: 67 / H:16 / S:32 17 MB (FAT16/4) doesn't work (non-system disk)

  • C: 67 / H:16 / S:32 17 MB (FAT16/4) with spf=0x40 instead of 0x100: works

  • C: 127 / H:16 / S:32 32 MB (FAT16/4) with spf=0x40 instead of 0x100: works

  • C: 135 / H:16 / S:32 33 MB (FAT16/6) with spf=0x60 instead of 0x100: works

  • C: 255 / H:16 / S:32 64 MB (FAT16/6) with spf=0x40 instead of 0x100: doesn't work (non-system disk)

  • C: 255 / H:16 / S:32 64 MB (FAT16/6) with spf=0x40 instead of 0x100: doesn't work (non-system disk)

  • C: 255 / H:16 / S:32 64 MB (FAT16/6) with spf=0x80 instead of 0x100: works

  • C: 507 / H:16 / S:32 127 MB (FAT16/6) with spf=0xFF instead of 0x100: doesn't work (non-system disk)

  • C: 507 / H:16 / S:32 127 MB (FAT16/6) with spf=0xFE instead of 0x100: doesn't work (non-system disk)

  • C: 359 / H:16 / S:32 90 MB (FAT16/6) with spf=0xC0 instead of 0x100, spc=4: doesn't work

  • C: 359 / H:16 / S:32 90 MB (FAT16/6) with spf=0xC0 instead of 0x100, spc=8: doesn't work

  • C: 183 / H:16 / S:63 90 MB (FAT16/6) with spf=0xC0 instead of 0x100: doesn't work (non-system disk)

  • C: 359 / H:16 / S:32 90 MB (FAT16/6) with spf=0xD0 instead of 0x100: doesn't work, hangs

  • C: 359 / H:16 / S:32 90 MB (FAT16/6) with spf=0xE0 instead of 0x100: doesn't work, hangs

  • C: 479 / H:16 / S:32 120 MB (FAT16/6) with spf=0xF0 instead of 0x100: doesn't work (non-system disk)

  • C: 511 / H:16 / S:32 128 MB (FAT16/6) with spf=0xC0 instead of 0x100: doesn't work

  • C: 511 / H:16 / S:32 128 MB (FAT16/6) with spf=0x80, spc=8 instead of 0x100: works

  • C: 515 / H:16 / S:32 129 MB (FAT16/6) with spf=0xC0 instead of 0x100: doesn't work

  • C: 763 / H:16 / S:32 191 MB (FAT16/6) with spf=0xC0 instead of 0x100: doesn't work

  • C: 767 / H:16 / S:32 192 MB (FAT16/6) with spf=0xC0 instead of 0x100: doesn't work

  • C:1019 / H:16 / S:32 255 MB (FAT16/6) with spf=0x80,spc=16 works

  • C:1023 / H:16 / S:32 256 MB (FAT16/6) with spf=0x80,spc=16 works

  • C: 741 / H:16 / S:33 191 MB (FAT16/6) with spf=0xC0 instead of 0x100: doesn't work (non-system disk)

  • C: 1006 / H:14 / S:48 330 MB (FAT16/6) with spf=0xC0 instead of 0x100: doesn't work (non-system disk)

  • C: 510 / H:16 / S:48 191 MB (FAT16/6) with spf=0xC0 instead of 0x100: doesn't work (non-system disk)

  • C: 620 / H:16 / S:62 300 MB (FAT16/6) with spf=0x100,spc=16: doesn't work (non-system disk)

  • C: 620 / H:16 / S:62 300 MB (FAT16/6) with spf=0x80,spc=32: doesn't work (non-system disk)

  • C: 620 / H:16 / S:62 300 MB (FAT16/6) with spf=0x80,spc=32: doesn't work (non-system disk)

  • C: 262 / H:16 / S:63 300 MB (FAT16/6) with spf=0xFC,spc=16: doesn't work (non-system disk)

  • C: 262 / H:16 / S:63 300 MB (FAT16/6) with spf=0xC0,spc=16: doesn't work (non-system disk)

  • C: 514 / H:32 / S:32 257.5 MB (FAT16/6) with spf=0xFC,spc=16 works

  • C: 1005 / H:32 / S:32 503 MB (FAT16/6) with spf=0xFC,spc=16 works

  • C: 1001 / H:5 / S:52 127 MB (FAT16/6) with spf=0xC0,spc=8 doesn't work (non-system disk)

  • C: 1001 / H:5 / S:52 127 MB (FAT16/6) with spf=0xFC,spc=8 doesn't work (non-system disk)

  • C: 127 / H:16 / S:32 32 MB doesn't work (non-system disk)

  • C: 479 / H:8 / S:32 60 MB doesn't work (non-system disk)

  • C: 511 / H:8 / S:32 64 MB doesn't work (non-system disk)

  • C: 197 / H:32 / S:32 99 MB (FAT16/4) with spf=0xC0 instead of 0x100: doesn't work (non-system disk)

  • C:1023 / H:8 / S:32 128 MB doesn't work (non-system disk)

  • C:1023 / H:16 / S:32 256 MB doesn't work (non-system disk)

  • C:1019 / H:16 / S:32 255 MB doesn't work (non-system disk)

  • C: 511 / H:16 / S:32 128 MB doesn't work (non-system disk)

  • C: 511 / H:16 / S:32 128 MB (FAT16/4) with spf=0x40 instead of 0x100: doesn't work (non-system disk)

  • C: 503 / H:16 / S:32 126 MB (FAT16/4) with spf=0x40 instead of 0x100: doesn't work (non-system disk)

Limits are:

  • spf Value only 8-bit and only some values are possible.
  • Size 503MB for now.

The Card can be hacked to be a SUMO SCSI Card with reasonable effort (by omitting U12-14). Then the ASPI Driver ZHA.SYS and ZDRV.SYS will work.

Parts

42
QtyValueFootprintReferences
10100nCapacitor_THT:C_Disc_D8.0mm_W2.5mm_P5.00mmC1, C2, C3, C4, C5, C6, C7, C8, C9, C10
3220E/330EResistor_THT:R_Array_SIP8RP2, RP3, RP4
2100nCapacitor_SMD:C_1206_3216Metric_Pad1.33x1.80mm_HandSolderC13, C14
274LS688Package_DIP:DIP-20_W7.62mmU7, U8
2MountingHoleMountingHole:MountingHole_3.5mmH1, H2
11N4001Diode_THT:D_DO-34_SOD68_P12.70mm_HorizontalCR1
122u/16Capacitor_THT:CP_Axial_L11.0mm_D5.0mm_P18.00mm_HorizontalC11
127C128Package_DIP:DIP-28_W15.24mmU6
1470pCapacitor_SMD:C_1206_3216Metric_Pad1.33x1.80mm_HandSolderC12
14k7Resistor_THT:R_Axial_DIN0309_L9.0mm_D3.2mm_P12.70mm_HorizontalR1
14k7Resistor_THT:R_Array_SIP8RP1
153C80Package_DIP:DIP-40_W15.24mmU5
16116Package_DIP:DIP-24_W15.24mmU4
174LS125Package_DIP:DIP-14_W7.62mmU2
174LS14Package_DIP:DIP-14_W7.62mmU3
174LS175Package_DIP:DIP-16_W7.62mmU1
174LS245Package_DIP:DIP-20_W7.62mm_LongPadsU9
1BIOSConnector_PinHeader_2.54mm:PinHeader_2x02_P2.54mm_VerticalJP1
1Bus_ISA_8bitmy_own_conn:BUS_XTJ2
1DACK/DRQConnector_PinHeader_2.54mm:PinHeader_2x04_P2.54mm_VerticalJ4
1IOConnector_PinHeader_2.54mm:PinHeader_2x03_P2.54mm_VerticalJP2
1IRQConnector_PinHeader_2.54mm:PinHeader_2x05_P2.54mm_VerticalJP3
1MIC5219-2.85YM5Package_TO_SOT_SMD:SOT-23-5U11
1PAL16L8Package_DIP:DIP-20_W7.62mmU10
1SCSI InternConnector_PinHeader_2.54mm:PinHeader_2x25_P2.54mm_VerticalCN1
1SCSI externConnector_Dsub:DSUB-25_Female_Horizontal_P2.77x2.84mm_EdgePinOffset7.70mm_Housed_MountingHolesOffset9.12mmJ1
1TRMPWRSELJumper:SolderJumper-3_P1.3mm_Bridged12_RoundedPad1.0x1.5mmJP4
1TermPowerConnector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_VerticalJP6

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Questions

How big is the NCL501 PCB?

It measures 135 × 97.8 mm and has 2 copper layers, 1.6 mm thick.

What parts does the NCL501 use?

42 parts, built around the PAL16L8-5JC, 74LS125DC, 74LS245SC and 27C128-15. 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 NCL501 KiCad files?

From the roberto314/NCL501-SCSI-8-Bit repository on GitHub, at the commit this page was made from: the board is schematic/NCL501/NCL501.kicad_pcb and its schematic schematic/NCL501/NCL501.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the NCL501 design in my own project?

Its repository states no licence, so its author keeps all rights: ask roberto314 before reusing the design.