Universal 2704/08
PROMMER with USB or RS232C interface

Assembly guide

Fits into a standard 60mm x 100mm plastic case

Table of Contents

Introduction...................................................................................................................................... 4

Parts list............................................................................................................................................ 5

Assembly.......................................................................................................................................... 7

Step 1: Add resistors and diodes............................................................................................... 7

Step 2: Add Capacitors............................................................................................................. 8

Step 3: Add Transistors and Pin Header .............................................................................. 9

Step 4: Add Microcontroller STM32........................................................................................ 10

Step 5: Add the IC U1 and the two Voltage Regulators ..................................................... 11

Step 6: Add LED and EPROM socket to the TOP side ...................................................... 12

Step 7: Clean and dry the board, inspect.............................................................................. 13

Preparing for use............................................................................................................................ 14

Operating under Windows............................................................................................................ 15

Introduction

Thank you for choosing this Universal 2704/08 PROMMER kit!

This kit is not a beginner’s kit, but thanks to the use of through-hole components and open PCB

layout, the complexity of assembly is intermediate.

If the builder has some experience assembling other intermediate level PCBs, or even advanced beginners’ level, this kit should pose no problems.

Note that the Universal 2704/08 PROMMER kit does not include any power supply, but requires an externally Micro USB connection with stable 5V DC capable at min. 500mA current (2.5Watts).

The discussed Rev 2.1 board can be operated via Serial USB interface or TTL RS232 port (J2). J2 needs to be connected to a standard RS232C converter (optional) or any other TTL RS232 interface.

Before starting assembly, carefully inspect the contents of the kit, to ensure that no parts are

missing, and that no damage has occurred during transport. Also make sure to read (at least skim)

through this document, to be familiar with the steps required, but also to notice all assembly tips

that are located throughout the guide.

If you are building from the kit and you make your own modifications, you cannot rely only on this guide, but will need to examine the remaining documentation like schematics.

Be particular careful with your working environment concerning electrostatic charges that may damage the electronic components. The kit includes ESD sensitive MOSFETS components. Using a well earth grounded strap is recommended.

Parts list

Part type

Value/
designation

Check

marks

Pos

1x DIP-14 IC

74LS06

1x TO-251-3 MOSFET

AOI444

n/a

1x TO-92L 5V Regulator

L79L05_TO92

1x TO-92L Transistor

BC337B

in one

piece (7 pins)

1x PinHeader_1x01_P2.54mm_Vertical

Conn_01x01

1x PinHeader_1x02_P2.54mm_Vertical

Conn_01x02

1x PinHeader_1x04_P2.54mm_Vertical

Conn_01x04

2x Capacitors

100nF

C4, C3

2x LED RED(D3) and GREEN(D2)

LED small

D2, D3

3x R_Axial_DIN0204 RESISTOR

5.1k

R7, R1, R6

1x R_Axial_DIN0204 RESISTOR

20k

1x Capacitor 50V

1nF / 50V

1x R_Axial_DIN0204 RESISTOR

6.8k

1x R_Axial_DIN0204 RESISTOR

4.7k

2x R_Axial_DIN0204 RESISTOR

10k

R4, R5

1x BluePill_STM32F103C MICROCONTROLLER

BluePill

1x CP_Radial_D5.0mm_P2.50mm CAPACITOR

3.3uF / 50V

1x CP_Radial_D5.0mm_P2.50mm CAPACITOR

220uF / 16V

1x D_DO-35 SCOTTY DIODE

BAT41

1x HW-520_module VOLTAGE REGULATOR

HW520

1x DIP_Socket-24 ZERO FORCE INSERTION SOCKET

Quick Connect SUPP24

1x MT3608_module VOLTAGE REGULATOR/BOOSTER

MT3608

(OPTION) 1x RS232C ADAPTER MODUL

RS232 TTL > V24

OPT1

TOP PCB side

This side is populated with a 24 pin Quick Connector J1 and two LED indicators (D2, D3). All other components have to be placed on the bottom side.

BOTTOM PCB side

Assembly

Step 1: Add resistors and diode

It is advantageous to solder the resistors and diode first. This helps placing the components flush and close to the PCB surface. R1,R2,R3,R4,R5,R6,R7 and R8 together with D1 are placed and soldered. Pay attention to the diode orientation! The black ring is to the left (see photo).

Use bill of material, to check-mark components soldered.

Always check values with your Ohm-meter before soldering.

Step 2: Add Capacitors

The five capacitors are all located in a group on one BOTTOM side of the PCB. The shape of C1, the 1nF/50V type is a little bit larger than C3 and C4. The hole distance of the PCB is a unfortunately a bit to narrow, so you have to bend the capacitor pins to fit.

The electrolytic capacitors are placed with the (-)minus side to the white marking on the PCB.

Take care for correct orientation of both electrolytic capacitors C2 and C8.

Step 3: Add Transistors and Pin Header

There is one 7-pin Pin Header that needs to be broken into 4,2 and 1-pin. Solder to the shown location at J2, J3 and J4.

Next are the transistor Q1, the -5V regulator U2 and the MOSFET Q2.

Make note of their orientation, fit them with the flat side matching the legend on the PCB.

For the MOSFET Q2, make sure the orientation in relation to pin one is as shown in the picture below. The plastic housing must face towards the resistor R4. It also is a good idea, to solder IC- pin sockets into the PCB and later insert the components into the socket. (Pin sockets are not provided in this DIY build)

Tip, you may use painters masking tape to hold the components in position, so they stay in place when you turn the board over. Once the board is turned so the pins are facing you, solder the pins on opposing corners of each part. You can now remove the painter’s tape. Inspect how well seated the components are. If a component is misaligned, heating the already soldered pins lets you tweak its position. Once all components are properly located, the remaining pins can be soldered in one go.

Using painters’ tape to temporarily hold components and pin headers

Step 4: Add Microcontroller STM32

The STM32 controller boards comes with two yellow pin headers. They will connect the STM32 to the main PCB. For easy soldering, it is highly recommended to cut the pins short as sown in the following picture.

cut

short

to same

length

Reason is the solder quality that is needed. Long pins on the PCB or STM32 board side will make soldering difficult and solder bridges may easily occur.

Before soldering the STM32 board, you may test the board by connecting to an USB power supply. The LED on the STM32 board should light up. Left green LED should flash for a few seconds and the other red LED has to stay on bright. Now you now, you are ready to go.

Tip: place the shortened pin headers into the main PCB and put the STM32 board on top.

Now all pins are aligned perfectly and you can solder the pin header to the STM32 board and afterwards to the main PCB.

Check with a magnifier for any solder bridges. Alternatively, you may use pin sockets on the main PCB for later disassembly.

Step 5: Add the IC U1 and the two Voltage Regulators

When mounting the two Voltage Regulators boards, the position and orientation can be identified by the marking on the PCB. There are two methods to solder the boards to the main PCB.

The boards are placed flush to the main board, well aligned to the large solder pads. With the solder iron, you can easily apply solder into the holes. This will nicely join the boards to the PCB (as seen in the picture below)
You may use wire or single pin header pins, and solder them to the main PCB and afterwards place the voltage regulator boards on top. Make sure, a good electrical contact is made.

The large board is providing the programming voltage of 26V, the smaller board provides -12V and +12V. In total, nine solder joints have to be made for both boards.

Result of method 1. Check the other side of the PCB, that solder has flown all way thru.

Finally solder U1 (74LS06) to the PCB. The IC notch has to match the PCB marking and faces to the front edge of the PCB.

Step 5: Add LED and EPROM socket to the TOP side

When mounting the 3mm LEDs, the polarity can be identified by the flat on the LED housing, or the shorter leg. The short leg and the flat identify the (negative) cathode terminal, and connects to the square solder pad, also indicated by a white square on the silk screen.

Position D2(green Power LED) and D3(red Programming LED) in the desired height.

Before soldering the EPROM socket, you have to clean und cut all solder joints underneath the socked short. If not, the socket cannot sit flat on the PCB and the pins may not reach fully the other side. When the socket is almost flat to the PCB, solder it in place. (a small gap will work fine).

YOU MADE IT !! CONGRATULATIONS !!

Step 8: Clean and dry the board, inspect

The board should be thoroughly cleaned when the soldering has been completed.

To dissolve organic rosin-based fluxes Isopropyl/isoprop based cleaners work very well. Do NOT use acetone or acetone-based cleaners, as they will damage the plastic parts assembled on the board.). Use a toothbrush or similar brush to clean the board. You may after cleaning with alcohol or spirits use mineral-free water to rinse the underside of the board. If you used a citrus based cleaner, rinsing is required. After cleaning, the board needs to dry completely.

After cleaning, do a thorough and complete inspection. Look for solder bridges, cold or incomplete joints and similar defects. If you find problems during inspection, you should be able to correct them, but remember to clean the board again if you need to add (or remove) solder.

Before powering up the device, check the following items:

- Check on J3, that +5V and GND are not shortened

- Check U2 and Q1 for correct orientation. U2 has to be the 79L05 regulator,

- Check the Q2 MOSFET for correct orientation (plastic housing towards R4)

- Check that VIN and VOUT of board M2 and M3 are all connected to the main PCB

- Check that U1, the 74LS06 is placed in the correct orientation and position

Now connect the USB cable to the STM32 M1 board. The LED on the STM32 board should light up. Left green LED should flash for a few seconds and the other red LED has to stay on bright. If this does not happen, you must have a short on the +5V rail or the STM32 board is not working.

If the board powered up as described, you can measure on J3 or J2 the 5V DC rail. This voltage should be 4,9V or higher. If the voltage is below, your USB power connection is insufficient and the PROMMER may not work properly. Also check regulator and other components. They should stay cold as long the PROMMER is not activated by software or RS232 terminal.

Preparing for use

Within the kit are 4 plastic standoffs included to allow the PROMMER to be placed nicely onto a flat surface.

Alternatively, the board may be assembled into a standard 60mm x 100mm plastic case. The screw holes of the PCB should match the mounting post of such a case.

Installing the Software

Follow the installation instruction in the Info.txt file. The PROMMER USB interface uses a Maple Serial driver protocol, which is a standard driver on newer Windows installations (usbser.sys).

This Software was tested and works on

- Windows 7,8,10 32bit & 64bit

- Windows XP 32bit & 64bit (legacy drivers for Windows XP (yes, they work!))

- RS232C Terminal mode (with adapter connected to the RS232 port)

- Use Windows or any other OS in Terminal Mode with a Maple driver

Using the PROMMER in older Windows Versions, DOS, Linux or MACOSX, you have to use a Terminal program for it and the RS232C Adapter Option.

The Prommer connects to the PC via USB or RS232. In both cases as a serial port.

So, you can connect with the Prommer by a Terminal program via USB or a proper serial cable.

If you plan to use the serial RS232C adapter Option you do not need to install any special drivers. The default RS232C setting are: 9600 Baud 8N1, no hardware RTS or CTS flow control.

The advantage of the RS232C adapter option is, you may use the PROMMER with any OS and any kind of vintage equipment back to the early 60's. The PROMMER supports a “full” independent Serial Terminal mode, like in the old days.

OPERATING UNDER WINDOWS

For Windows, a "Prommer_2708.exe" program is included to communicate with the PROMMER using a simple Windows User Interface. This program also allows you to modify the max. 2kB PROMMER buffer, if needed.

WINDOWS USER INTERFACE

Starting Prommer_2708.exe the first time, you may see the Message: PROMMER not found”. In this case, you have to select the COM port that the PROMMER driver is using.

Go to the Control field and select from the Drop-Down menu the PROMMER port. Usually, it is named \Device\USBSERxxx

You may try out other ports, if your port naming is different.

If you have once selected the correct COM port, this information will be stored in a PROM2708.ini file and reloads automatically, every time you start the program again.

Once the COM port selection is valid, the message

will appear as well the current PROMMER

software version, which should be Version 2.3a

and above.

If none of the COM ports allows you to connect to the PROMMER, you may need to install the MAPLE USB driver for Windows, that is located in the directory of the program.

The driver section includes drivers for

If none of the above works on your Windows installation, you may try to connect the J2 Serial connector to a known working RS232 TTL to USB interface adapter to your PC.

Connect the RS232 TTL cable 1:1 to the corresponding silkscreen terminals.

RX-RX and TX-TX are going to be connected, no “crossover”!

Baud rate is 9600 Baud 8N1 per default

Soldering a bridge at (3) will reduce to 300 Baud, or at (1) change to 2-Stop Bits.

If you are using the RS232 Serial Interface, you need to set the correct corresponding Baud rate in your Terminal program or in the Prommer_2708.exe program.

Go to PORT SETUP and select 9600 Baud and press “Apply”.

Now the program should be able to communicate with the

PROMMER board.

Of course, you also may use a terminal program instead.

If you prefer to use the PROMMER without a modern PC, just together with your vintage equipment, you can do so by connecting to the RS232 TTL port J2.

The RS32C Option will need a RS232 TTL to RS232C adapter, that needs to be connected to J2. J2 will provide the voltage supply for the adapter.

In this case, you have to supply 5V to the PROMMER board, either by USB or by the J3 +5V/GND connector. It is possible to use a +5V Lithium Battery module, so the PROMMER is battery powered for max. flexibility. Via the USB port, the Battery module will be charged. This type of power supply is not provided and needs to be created by the owner himself.

TERMINAL USER INTERFACE

Open your preferred terminal program and press “ENTER”. The following text message will appear:

„H“ will list all availabe terminal commands. They should be selfexplaing.

You may transfer data to or from the Prommer by S19 Motorola standard, Intel i8hex or just plain binary data protocol. Please make sure, your preferred Terminal program can actually transfer data according these three methods.