From 3bfbc7d3232a16a2a08be4911997e0949d877e9f Mon Sep 17 00:00:00 2001 From: Tom Nisbet Date: Fri, 25 Nov 2022 08:25:49 -0500 Subject: [PATCH] doc updates for PCB --- docs/index.md | 8 ++++---- docs/pcb.md | 30 ++++++++++++++++++++++-------- docs/prom-families.md | 11 ++++++----- 3 files changed, 32 insertions(+), 17 deletions(-) diff --git a/docs/index.md b/docs/index.md index de332d1..c608357 100755 --- a/docs/index.md +++ b/docs/index.md @@ -66,10 +66,10 @@ files as well. The default code programs 28C series chips using Arduino Nano har use this version, just compile and upload it to the Arduino. **Note well** that this code has been optimized for the Aduino UNO and Nano hardware so -that it can run quickly enough to meet 28C series chip timing requirements for SDP -unlocking. To use different Arduino hardware, like the Micro, the board-specific code in -PromDevice.cpp and PromAddressDriver.cpp must be change to match the port mappings between -the ATmega chip and the Arduino I/O pins. +*that it can run quickly enough to meet 28C series chip timing requirements for SDP +*unlocking. To use different Arduino hardware, like the Micro, the board-specific code in +*PromDevice.cpp and PromAddressDriver.cpp must be changed to match the port mappings +*between the ATmega chip and the Arduino I/O pins. Because the Arduino has limited code and RAM space available, only one PROM driver is compiled in at a time. To change drivers, uncomment the desired PROM_IS_xx line in diff --git a/docs/pcb.md b/docs/pcb.md index 58de240..7c7162c 100644 --- a/docs/pcb.md +++ b/docs/pcb.md @@ -1,5 +1,5 @@ --- -title: PCB +title: Printed Circuit Board description: "TommyPROM Arduino 28C256 programmer PCB" has_children: false nav_order: 35 @@ -12,10 +12,10 @@ there are now some PCB versions. ## 28C256 PCB -I built a PCB version for the 28C256 and 28C64 chips because so many burns of these were -needed for a SAP-1 TTL breadboard computer. The PCB version with the ZIF socket was much -easier to work with, compared to prying the chips out of a breadboard without disturbing -any of the wires. +A PCB version for the 28C256 and 28C64 chips was built to support a SAP-1 TTL breadboard +computer. This project required a lot of burns for its microcode and the PCB version +with the ZIF socket was much quicker than prying the chips out of a breadboard without +disturbing any of the wires. The [KiCad design files](https://github.com/TomNisbet/TommyPROM/tree/master/schematics) are in the project repo. @@ -28,8 +28,22 @@ A new PCB is in progress for 32-pin EEPROM and Flash chips. This design uses a headers that allow any of the signals to the target chip to be re-routed. The default configuration, with just jumper shunts installed, is wired for the SST39SF0x0 chips. -Many other chips, particularly if they follow JEDEC standards, can be supported be adding -just a few jumpers. +Many other chips, particularly if they follow JEDEC standards, can be supported by +removing shunts and adding just a few jumper wires. -Chips with few pins can also be supported. There are power pins in place to support +Chips with fewer pins can also be supported. There are power pins in place to support 28-pin and 24-pin chips with a shunt to the correct VCC pin. + +Power inputs and a switch are provided to support older flash and EEPROM chips that need +higher programming voltages. Many of these chips just need a higher voltage, like 12V, +applied to the VPP pin continuously during the programing and verification cycle. In +normal operation, the 5V VCC signal is also applied to the VPP pin. The board has VPP +inputs for two voltages. Applying 12V to __VPP In High__ and 5V to __VPP In Low__ lets +the VPP output be switched between these two voltages using a manual slide switch for +programming. + +For chips that require a high voltage VPP pulse during programming, some external +switching circuitry will be needed to allow the Arduino to control the VPP voltage. There +is a header connected to the unused D13 pin that can support this. See the +[Intel 8755 version of the hardware](hardware/#intel-8755a-hardware-version) for an +example of voltage switching by TommyPROM. diff --git a/docs/prom-families.md b/docs/prom-families.md index 07e4adb..3d23f98 100644 --- a/docs/prom-families.md +++ b/docs/prom-families.md @@ -49,11 +49,12 @@ window. ## 28C EEPROM -The 28C series EEPROMs, specifically the 28C256, are the original chips that TommyPROM supported. As a result, these have the best support, with all of the interactive features of the command line. In addition the basic read and write operations, there are also -commands to enable and disable the -[Software Data protection (SDP)](../28C256-notes) features of 28C chips. There is also -support for the fast block write mode of these chips, allowing a 32KB chip to be -programmed in just a few seconds. +The 28C series EEPROMs, specifically the 28C256, are the original chips that TommyPROM +supported. As a result, these have the best support, with all of the interactive features +of the command line. In addition the basic read and write operations, there are also +commands to enable and disable the [Software Data protection (SDP)](../28C256-notes) +features of 28C chips. There is also support for the fast block write mode of these +chips, allowing a 32KB chip to be programmed in just a few seconds. ## 27C EPROM