ISP Connector	I bought a programmer before I knew exactly what systems that I intended to use it with and went for just about the cheapest option that I thought would do the job. It appears that all of the PET SD card "disk drives" use a 6-pin In-System Programming (ISP) connection, unlike the kit shown below, my programmer did not have a 10 to 6 pin adapter, so I had to purchase one of these separately. As it turned out though, I have not needed to program the MCUs "in-system", I install the boot-loader using my mini development board and add the application firmware via the SD card as described on my petSD+ firmware page.
Device Drivers	The ebay listing had a link to a download site for the USB drivers for the device. When I downloaded it, my Anti-virus program flagged it as containing a virus, I don't know whether this was a "false positive" or whether there is an issue with the file, but I didn't want to take the risk. Inspection of the archive file showed that, as well as containing what appeared to be a download utility (written in Chinese), it used a library called libusb-win32 to install the required DLL. This  libusb-win32 library is an Open Source project hosted on SourceForge, I downloaded the latest version of the library and used it to install the USB driver on my 64-Bit Windows 7 Pro laptop.
Software	As I mentioned, the archive contains a Chinese of a program called PROGISP Version 1.6.6, I did not need to use this, having used AVRDUDE instead. I don't know whether PROGISP is any good or not, but Version 1.7.2 in English is available here, password www.eca.ir. Caution : Use at your own risk, the website is located in Iran and the accompanying "read-me" is in Arabic. The site appears to be an Iranian on-line electronics store, again, in Arabic.

 

Other Programmers
USBASP programmer	There are lots of cheap (£2 - £3) USBASP programmers, such as  this one, available on ebay. (Try searching for USBASP) Note : The ISP connector on petSD+ is the 6-pin version, if the programmer does not have one included, you will need a 10-pin to 8-pin adapter.

USBASP Programmer Firmware Upgrades
When I tried to use my cheapo USBASP programmer, I found that, although the programmer seemed to work without problems, warning messages were displayed by AVRDUDE, e.g., : avrdude: set SCK frequency to 16000Hz avrdude: warning: cannot set sck period. please check for usbasp firmware update. If you "Google" that warning message, you will find that it is a common problem with the cheap Chinese USBASP programmers such as mine. It seems that many, if not all, of those cheap programmers come with an older version of the firmware which does not support setting the SCK frequency. However, on some devices, it is fairly easy to update the firmware. *** Disclaimer *** Upgrading the firmware of your USBASP device is likely to be trouble free. However, you should be aware that there is always the possibility that you could "brick" the device. Use the following information at your own risk - but given the cost of these things, it's hardly a major gamble!
Some programmers, such as the LC Technology USBASP V2.0 shown above, have a jumper position (in this case, marked as JP2) provided to enable reprogramming of the on-board MCU. The jumper pins are likely to be missing, so you will need to install a jumper onto the board yourself.
The USBASP design was originally produced Thomas Fischl, a Version 2 design of the board is available from a large number of Chinese sellers on ebay. They come with little or no documentation, but the same design is being sold by protostack.com in Australia, quoting from their website, protostack are "an online retailer of electronic components for students, hobbyists and electronic engineers. We are based in Brisbane, Australia". Protostack sell the same device with their part number AC-PG-USBASP and have written a very good User Guide for the device which covers installation, usage and upgrading of the device firmware. You can download a copy of this manual from Protostack here, or from my petSD+ Documentation page.
The USBASP programmer contains an embedded microcontroller - usually an Atmel ATMega8/88, upgrading the firmware requires uploading the new firmware file to the MCU. The description of the USBASP programming jumper in the protostack manual as "Self Program" is a bit of a misnomer - the USBASP can't program itself - you need another programming device to do it. There are various threads on the web from people with Arduinos that have used the Ardiuno to do this, including this one from Roget Clark in Australia that also describes how to back up the original firmware first. Since I don't have an Arduino and those USBASP programmers are so cheap that I bought 2, I was able to use one to upgrade the other. Even when upgrading one USBASP using another, there are a number of different procedures described in various places on the web, the procedure below may not be the "correct" one, but it worked for me - try it at your own risk.
Download the latest firmware from Thomas Fischl's site :   - At the time of writing, this was version usbasp.2011-05-28	usbasp.2011-05-28
Extract the binary for the MCU installed on your programmer, e.g. :	usbasp.atmega8.2011-05-28.hex
Ensure that both USBASPs are configured for +5VDC
Connect the USBASP to be used for reprogramming the target to the computer	(Either old or new firmware is OK)
Fit jumper JP2 to the target to activate the USBASP firmware update function
Connect the target USBASP to the first USBASP with a 10-way ribbon cable
As when programming petSD+, check that you can talk to the target, e.g. : should return the status of the Fuses for an ATMega8 (device code m8), e.g,:	avrdude -B 50 -c usbasp -p m8 Fuses OK (E:FF, H:D9, L:FF)
Note : If you are using one device with older firmware to upgrade another, you can expect to see, and can ignore, the SCK warning messages from AVRDUDE :       avrdude: set SCK frequency to 16000Hz       avrdude: warning: cannot set sck period. please check for usbasp firmware update.
If the target device fuse settings are different from those specified in the readme.txt file on Thomas Fischl's site, set them as shown. This sets the MCU to use an external crystal, rather than its internal RC oscillator for timing	avrdude -c usbasp -p m8 -u      -U hfuse:w:0xc9:m      -U lfuse:w:0xef:m
Provided that the fuses are written without error, we can re-flash the programmer's application firmware :
Provided that AVRDUDE verifies the flash and does not report any other errors, the upgrade is complete and the program enable jumper can be removed.

 

Some Background Information . . . believed accurate, but e&oe !

Based on various snippets that I have picked up from various websites and user forums, it appears the the cheap Chinese USBASP clones fall into two types :

Version 1 - a clone of  Thomas Fischl's original USBASP
Version 2 - an updated version with a slightly different design
The original design included three jumpers to configure some options, not all of these jumpers are present on the Chinese clones, they may be missing entirely or, in the case of the voltage select jumper, may have a 0 ohm resistor installed instead. There is some inconsistency on how the jumpers are labeled, even on Thomas Fischl's site, where the circuit diagram is annotated as per the Version 1 column in the table but the readme.txt file describes the jumpers are per the Version 2 column in the table. Function (Original design) Jumper ON  Version 1 Version 2 SCK clock speed Slow JP1 JP3 (J3) Firmware upgrade Enabled JP2 JP2 (J2) Supply target with USB +5VDC Yes JP3 JP1 (J1) The readme.txt file on Thomas Fischl's site, describes the function of J3/JP3 and states that it was used to control whether the target MPU was supplied with +5VDC from the USB port, or whether the MCU had its own supply. Both versions of the Chinese clones that I have looked at include a 5V to 3.3V voltage regulator and the option to supply the target MCU with either 3.3VDC from the regulator, or 5VDC from the USB port. The version 1 boards have a hardwired link (a 0 ohm resistor) fitted to select +5V and the version 2 boards have a two position jumper fitted, sometimes, but not always, annotated as JP1. In the readme.txt file on Thomas Fischl's site, J2 /JP2 was described as a jumper to enable firmware upgrade, and remarks that the device is not self-upgradeable, which makes sense, although the circuit diagram refers to the jumper as "Self-programming", I think that this is just a result of a minor translation problem - it should be more accurately described as "upgrade enable" or similar. As noted above, another device is required to re-flash the programmer's firmware. The version 1 boards have an unlabeled jumper The original Fischl design used a hardware jumper, J1/JP1, to select between two fixed SCK speeds, one at 8kHz for target MCUs with a low clock speed (<1.5MHz) and the other at 375kHz for targets with a faster clock speed. This area is where there seems to be some divergence between the Fischl design and the Chinese clones. In what I have called the Version 1 design, this jumper is not present and the pre-loaded firmware does not recognise the AVRDUDE commands to set the programming speed. I was able to successfully program MCUs with my unmodified Chinese clones, it appears that the firmware supplied with the Version 1 clones automatically selected the slow SCK speed for MCUs running down to 1MHz. Even though programming was successful, it appears that AVRDUDE attempts to set a default clock rate, even without being commanded to, and so always generates the warnings about being unable to set the SCK speed when this fails. The clock speed select jumper has been reinstated on the Version 2 boards, labeled as JP/3, with new firmware, the Version 2 boards support setting the SCK speed either in software or using the hardware jumper.

ATMega Fuse Bits A comprehensive description of ATMega Fuse bits is beyond the scope of this discussion, but a few brief notes are worth mentioning. When a fuse bit is 0, it is PROGRAMMED When a fuse bit is 1, it is UNPROGRAMMED
Many AVRs, including the ATMega8 and ATMega1284P include an internal RC oscillator capable of providing a clock source of up to 8MHz. Alternatively, an external crystal oscillator can be used, selection between internal/external and internal frequency selection is done using Fuse bits.	Word hfuse lfuse   CKOPT CKSEL3..0 RC 1 0 0 0 1 Ext. 0 1 1 1 1
For devices with an internal oscillator, the device is shipped with the internal oscillator enabled and configured for a frequency of 1MHz. The meaning of the fuse words and bit values depend on the AVR in use, for an ATMega8, the table shows the clock control bits set by default and the values required to enable an external oscillator with a frequency of greater than 8MHz. Obviously, the primary reference for the Fuse bits is the appropriate Atmel MCU Datasheet, but on-line Fuse calculators, such as the ones at eleccelerator.com and engbedded.com are handy for quickly interpreting or calculating Fuse settings.