Introduction
EPROM Programmers come in different sizes and are designed to program individual chips with
- 32 pin
- 40 pin
- 48 pin
The 40 and 48 pin programmers are able to program larger memory devices as they have more address lines available. Allowing the user to manually set the most significant bit individual address signal lines using tri-state switches, allow these larger devices to be programmed by a 32 pin programmer.
- different footprints that either
- plug in directly
- or use additional adapters
before connecting to the ZIF zero-insertion sockets supplied with the programmer. In some cases the physical chip or the footprint is not always available.
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 available via a bespoke connector.
The user may know 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 solution is found, either be theory or by trail and error.
The object of this card is to design a PCB that can be used in a variety of ways depending which components are fitted This allowis 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 card is designed so that it does not fowl the lever.
Design
The design of the card is split in 3 parts where the first and last parts are similar and the middle part translates the desired signals.
Source - Plug to fit into the ZIF socket of the EPROM programmer
- Address Tri-state switches
- Header for additional address lines for 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. - These headers are repeated if required for jumper wires are used to connect directly to the output.
- 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.
Translation Section
- 2 x 12 way DIP switches
- Tri-state switches
Target - 48 pin ZIF Socket - Additional connector
- This allows up to the a maximum size 48 pin zif socket to be used.
- The headers are repeated so that jumper wires may be used.
- Tracks are marked with a section that allows them to be permanently be cut.
- Tracks may be reconnected using a header link
- 50 pin IDC connector to allow connection to non standard external cards
- Z88 external card socket connector
Parts List
| Description | Qty | Order Code | Min Qty | Price |
CONNECTOR, HEADER, THT, 2.54MM, 50WAY | 2 | 109-6994 | 1 | 2.47 |
SOCKET IC, ZIF, 48WAY | 1 | 1 | 13.09 | |
HEADER, 2.54MM, THT VERT, 24WAY | 6 | 5 | 2.84 | |
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 | 1 | 1.87 | |
SWITCH, DIL, TRI-STATE, 10WAY | 1 | 1 | 0.32 | |
RESISTOR, CARBON FILM, 2K2, 0.25W, 5% | 2 | 50 | 0.02 |
Circuit Diagram
The circuit diagram of this card can be viewed by clicking here (which will open in a new window).
