EPROM Programmer Card
- Vic Gerhardi
EPROM Programmer 32, 40 pin to 48 pin Adapter Translator Break-out Memory Card
Preface
Multifunction Card
Source and Target
I need to use an EPROM programmer (Source) to program Z88 cards (Target).
This had been done before using the Willem Programmer, a parallel cable, software running under Windows xp and a Z88 adapter card with the special Z88 connector fitted. With Windows xp reaching its "End Of Life," moving to Windows 8.1 was necessary. The parallel port method of connecting the EPROM Programmer was no longer supported, an alternative programmer was required. Although I managed to get the Z88 adapter card to work with a more 'up-to-date' software controlled USB EPROM programmer, it was found that there were several shortcomings using this approach.If a new "Printed Circuit Board" (PCB) was to be designed it would need to have a wider appeal. Only two people ever used the Z88 adapter card.
Changing the Footprint
The main stumbling block I found when changing a footprint that was not listed was that all programming changes are described with software. This is either propriety based, or could be changed by the user once the final configuration was known. I found that I needed several attempts hard-wiring the adapter, before I reached the final configuration that worked. Two problems needed to be addressed.
- Convince the EPROM Programmer (Source) that the chip is connected by
- changing the state of some of the signals that the chip does
- and set the remaining signals to the footprint that it is set.
- Redirecting the active programming signals to the (Target) device, be it
- a chip,
- or a connector to go to a card with the chip inside the card.
Using hardware switches and links to change the position of the signals for different footprints using different "Dual In Line" (DIL) or DIP based EPROM Erasers seemed like a good starting point. There are already adapters on the market that change the footprints from the 0.3" or 0.6" DIL to other footprints like PLCC, TSOP. These could be used in the (Target) location using (Zero Insertion Force) ZIF sockets if required.
Memory Card
Two further footprints may be fitted taking the place of the headers and the hardware wire links. This can save wiring memory chips manually.
This would allow up to four memory chips to be connected together with two different footprint design if desired.
The Eurocard card width of 100 mm with a patch area, allows fitting of
- an optional decode chip on the card allows address decoding for the chips on the card.
The other half of the decoder may be used as a card decoder allowing up to four of these cards are used. Up to 16 memory chips could be connected together. - or a connector allowing the card to be used in Euro-racks.
Introduction
EPROM Programmers are now software controlled. This works well if the chip type and footprint is in the database but what happens when a variation is required?
Connecting Memory chips in parallel to expand the overall memory size is a common requirement.
This break out card addresses both these applications. Firstly it allows the user to set in hardware, a source footprint to be translated into a target footprint, using either switches, jumpers or jumper leads. Larger memory devices that are not supported may also be programmed, by manually setting the most significant bit individual address signal lines to a 1 or 0 using the tri-state switches provided. This allows larger devices to be programmed in several steps using a 32 pin programmer. In some cases the physical chip or the footprint is not available. The user may know, for example, which signals need to be swapped, changed or held at a different logic level and would welcome a board to try different combinations before the final solution is found, either be theory or by trail and error.
- The source 48/40/32 pin headers
fit into the ZIF socket of the EPROM programmer. They may be fitted at either a 0.3" or 0.6" pitch.
- The target 64 way DIN41612 connector allows a plug and socket to be used.
Space is also provided for
- 32 pin
- 40 pin
- 48 pin
size ZIF sockets if required.
Additional tri-state switches are provided to take up the job that some adapters do holding chip select pins, for example, when the number of active pins from the programmer is at a premium.
In the case of some older 8-bit game computers and the Z88 card for example, the flash or EPROM chip is inside a plug-able module. The address and data lines are then only available via a bespoke connector.
Secondly four multiple memory chips may be connected together. The spacing of the sockets and headers allow either a 0.6" or 0.3" pitch devices tp be paralleled up together. A decoder chip layout is also provided.
All devices used are "through-hole" allowing easy soldering.
Note: The card may be used either with an EPROM programmer or a memory card, not both together. Use two cards should that function be required.
Object
of this card is to design a PCB that can be used in a variety of ways depending on which components are fitted This allows the user to have full hardware control of the signals by selecting switches for testing, or making permanent changes by using wired links.
The lever that grips the chip can either be at the top left-hand side or the bottom right-hand side of the ZIF socket. The source header at a 0.3" or 0.6" pitch may be fitted on the left or right-hand side of the board allowing both types of EPROM erasers to be used. These leaves the target to be on the opposite side.
Design
All components (apart from the Z88 Connector) are placed on a 0.1" matrix, allowing different components to be used (i.e. headers or connectors).
Up to four cards may be stacked, using the 64 way connector with stack-able headers for connections.
The target size of the card is Euroboard size max 100 x 160 mm or 37 x 58 - 0.1" pitch holes 1 mm holes.
The design of the card is split in 3 parts
- Source - plugs into the EPROM Programmer
- Signal Box - switches individual signals using DIP switches and jumpers
- Target - ZIF socket or connector plugs into the target device
Source and Target detail
The source and target footprints can be interchanged. They have the following specification in 2 parts.
- Footprint of 0.6" and 0.3' pitch holes to fit up to a maximum size 48 pin ZIF socket or
- Z88 connector
- A multi-purpose area with 0.6" and 0.3' pitch holes to be used for either
- a patch area to
- cut tracks
- hardware connect non standard signals together or
- fit an additional memory chip.
- a patch area to
As the source and target have two footprints each, this gives a maximum of four footprints on a card to be used.
Provisional Layout
Connector
A 64 pin DIN 41612 connector is used so that the card can be used with Eurocards. Smaller 0.1" connectors or headers may be used if desired.
This connector has all the signals the card uses.
Source - Plug to fit into the ZIF socket of the EPROM programmer
- Address Tri-state switches
- Header to connect additional address lines from Willeim programmers
- Space for 2 off 24 pin headers to be used for 48 pin programmers.
Shorter lengths may be fitted for the smaller sizes of programmers. - Headers may be placed at either 0.6" or 0.3" pitch.
- Additional holes for headers are repeated if required for jumper wires to be used to connect directly to the target.
- Tracks are marked with a section that allows them to be permanently cut.
- 64 pin DIN 41612 connector (2 row 0.1" pitch footprint) to allow connection from other Eurocards, daughter boards, or wiring looms using an IDC plug and socket to connect from other non standard external cards.
- Double row of headers may be fitted over the cuts, so that the tracks may be reconnected using header links.
Memory chips
Two source and two target memory chips may be connected together. They are 48 pin at 0.3" or 0.6" pitch. Smaller sizes many be used. This allows four memory chips to be connected with different footprints.
Signal Box
The signal box is used to change the position of the signals from the source to the target layout.
- Patch area for optional card and address decoder chip
- 2 x 12 way Translator DIP switches and headers with links to select the footprint for the source and destination devices.
- Tri-state switches to statically select the state of unsupported address lines.
Target - 48 pin ZIF Socket
- This allows up to the a maximum size 48 pin zif socket to be used. Other sizes may be used.
- Sockets may be 0.6" or 0.3" pitch.
- Headers are repeated if required for jumper wires to be used to connect directly to the source or they may be used for an additional memory device.
- Tracks are marked with a section that allows them to be permanently cut.
- Another row of headers if required, may be fitted the other side of these cuts, so that the tracks may be reconnected using header links.
- 64 pin DIN 41612 connector (2 row 0.1" pitch footprint) to allow connection to other Eurocards, daughter boards, or wiring looms using an IDC plug and socket to connect to other non standard external cards.
- Z88 external card socket connector
Circuit Description
D0 - D7, A0-A8, A10, A12
19 signals are connected in parallel
A9, A11, A13 - A17
go to the signal box and are split into three sections
- Left
- Normal
- Right
21 signals, three lots of 7
(Vpp or A18)
A19 - A23
6 are connected in parallel and switched by tri-state switches
Parts List
| Description | Qty | Order Code | Min Qty | Price |
CONNECTOR, HEADER, THT, 2.54MM, 50WAY | 2 | 109-6994 | 1 | 2.47 |
HEADER, S/LATCH, STR, 2.54MM, 50WAY | 2 | 221-5272 | 1 | 1.38 |
PLUG, DIN41612, R/A, B, 64WAY | 2 | 229-3654 | 1 | 2.21 |
PLUG, DIN41612, B, 64WAY | 166-1151 | 1 | 2.70 | |
PLUG, DIN41612, R/A, B, 64WAY | 109-6830 | 1 | 2.47 | |
SOCKET, DIN41612, B, 64WAY | 118-9273 | 1 | 3.83 | |
SOCKET, IDC, DIN41612, 64WAY | 935-9966 | 1 | 9.97 | |
SOCKET IC, ZIF, 48WAY | 1 | 1 | 13.09 | |
HEADER, 2.54MM, THT VERT, 24WAY | 6 | 5 | 2.84 | |
HEADER, 2.54MM, THT VERT, 32WAY 2 ROW | 202-5423 | 5 | 1.97 | |
HEADER, 2.54MM, THT VERT, 8WAY 2 ROW | 202-5410 | 10 | 0.60 | |
SWITCH, JUMPER, 1 WAY, SPST, SLIDE | 328-9758 | 1 | 0.63 | |
CRIMP LEAD, SKT, MICRO-FIT, 150MM | AR | 5 | 1.67 | |
JUMPER SOCKET, BLACK, 2.54MM, 2WAY | AR | 10 | 0.18 | |
HEADER, VERTICAL, 0.1", 8WAY | 1 | 588-775 | 5 | 0.28 |
HOUSING, 26AWG, 8WAY | 2 | 109-8717 | 5 | 0.46 |
RIBBON CABLE, IDT, 8WAY | 1 | 30m | 69.01 | |
SWITCH, DIL, SLIDE, 12WAY | 2 | 947-9090 | 1 | 1.87 |
SWITCH, DIL, 5WAY | 1 | 152-3998 | 1 | 0.41 |
SWITCH, DIL, TRI-STATE, 10WAY | 1 | 152-2013 | 1 | 0.32 |
SWITCH, DIL, TRI-STATE, 8WAY | 152-2011 | 1 | 0.70 | |
RESISTOR, CARBON FILM, 2K2, 0.25W, 5% | 2 | 933-9302 | 50 | 0.02 |
SN74LS139AN - IC, DECODER/DEMUX, 74LS139 | 1 | 959-2296 | 1 | 0.53 |
1N4148 - DIODE, STD RECTIFIER,75V, DO-35 | 161-1492 | 10 | 0.047 | |
SOCKET IC, ZIF, 48WAY | 113-6791 | 1 | 13.09 | |
SOCKET IC, ZIF, 40WAY | 116-9111 | 1 | 12.83 | |
SOCKET IC, ZIF, 32WAY | 113-6782 | 1 | 10.65 | |
SOCKET IC, DIL, 24WAY | 107-7325 | 1 | 2.05 | |
PCB, EUROCARD, FR2 | 117-2182 | 1 | 3.08 |
Circuit Diagram
The circuit diagram of this card can be viewed by clicking here (which will open in a new window).
Scratch Pad and Ideas
Card size 100 mm Eurocard width
Eurocard connector dimensions
Eurocard Connectors Types B, C, M, Q, R, and Enhanced Type C (Board- to- Board Application)