The SIMCheck series of testers can be very helpful in quickly and thoroughly testing RAM SIMMs/DIMMs, but is very expensive for even very old examples. Unfortunately the inventor of the device, David Y. Feinstein, passed away in 2019 and the company now seems to be defunct. Their website is still up, but things like firmware downloads are behind a broken login system.
I recently bought an old SIMCheck II in the hopes that it'd be possible to clone for hobby use. I guess the inventor was very concerned about cloning when the device was new, because many of its ICs (even jellybean logic) have their silk screens sanded off. Further, there's an Altera CPLD present. I haven't checked yet, but would be really surprised if its security bit was not enabled. Perhaps that could be brute forced with something like the DuPAL, but that's an area I'm not familiar with.
For now here are a couple of board shots and an IC list of what's known on the 'processing board'.
Also, my unit has firmware 1.52. I'll try to dump and post that. The latest firmware is 1.55. If you have one of these units with newer firmware, it'd be much appreciated if you could dump and post it.
SIMCheck II Processing Board
SIMCheck II SIMM Board
Processing Board Semiconductor List
U1: TX486DLC/E-40GA CPU
U2/U3: Unknown
U4/U5/U6: Unknown
U7/U8/U9: Unknown
U10: Unknown
U11: ADM-692AM MicroprocessorSupervisory Circuits
U12: MIC29150 Voltage Regulator
U13: Unknown
U14/U15: 74ACT00PC Quad 2-Input NAND Gate
U16: EPM1032LC44-10 Altera Max 7000 programmable logic
U17: Unknown
U18: Unpopulated
U19/U20: AM29F010-90PC 1MBit CMOS 5V Flash Memory
U21/U22: W24257AK-15 32K×8 HIGH SPEED CMOS STATIC RAM
U23: MAX232CPE Serial Driver
U24: SCC2691AC1N24 UART
U25: D71059C-10 Interrupt Control Unit
U26: D71055C-10 CMOS Parallel Interface Unit
U27: D71054C-10 CMOS Programable Timer/Counter
U28: MC74HC174AN CMOS Hex D Flip-Flop with Common Clock and Reset
U29: MM74HC244N Octal 3-State Buffer
U30: Unknown
U31: 317T Voltage Regulator
U32: LM317 Voltage Regulator
U33: Unknown
U34: LX8385 Low Dropout Positive Regulator
U35: Unknown
U36: Unknown
U37: CD54HC377E High-Speed CMOS Logic Octal D-Type Flip-Flop With Data Enable
U38: 24C01A 1K Serial EEPROM
U39: Unpopulated
U40: 74ACQ244PC Quiet Series Octal Buffer/Line Driver with 3-STATE Outputs
And a little background about what the device is and does...
SIMCHECK II is the third generation of memory testers from the company that pioneered the RAMCHECK and SIMCHECK product lines. Based on a powerful, high-speed 32-bit 486 processor and utilizing state-of-the-art time delay circuitry, it significantly enhances the time proven testing capabilities that previous SIMCHECK users have come to depend on. Access time resolution of 1nS, cycle time measurement, graphic setup of timing parameters, true 3.3V testing and its unprecedented high speed testing are among these enhanced capabilities that up until now were not available in a portable memory tester.
A recent addition to our product line is the SIMCHECK II se, a lower cost version of the SIMCHECK II that uses many of the power features employed by SIMCHECK II. Please refer to Section 3.3 to view a comparison between SIMCHECK II and SIMCHECK II se.
With the move to SDRAM technology in the market place, we have released the SIMCHECK II PLUS and the SIMCHECK II se PLUS packages. These packages include the Sync DIMMCHECK 168 for testing SDRAM/EDO/FPM DIMMs. Please refer to Section 8.1 for further information on the Sync DIMMCHECK 168 Adapter.
SIMCHECK II tests all the standard 30/72-pin SIMM memory modules with sizes up to 4Gx40 and its modular design allows for virtually unlimited growth with optional adapters. Currently available adapters support SDRAM/EDO/FPM DIMMs, SO DIMMs, memory cards, and SOJ DRAM chips. If you have purchased a SIMCHECK II PLUS or a SIMCHECK II se PLUS, your tester can support the SDRAM/EDO/FPM DIMMs without an extra adapter.
Using our proprietary algorithms, SIMCHECK II runs a thorough test on the memory module, testing every memory cell. All chips (bits) are tested simultaneously to yield a faster test and to enable the instrument to detect errors that are caused by interference among the chips on the module. SIMCHECK II is not merely a go/no-go tester. In fact, it explicitly identifies the faulty bits within a defective module, and provides other important repair related information. While 100% accuracy in memory testing is technically impossible (See Appendix B), SIMCHECK II achieves a high degree of accuracy in detecting bad memory devices.
Since SIMCHECK II is fully automatic and extremely user friendly, anyone can use it with great ease. Its full graphics LCD display shows clear instructions and test results. It has Zero Insertion/Removal Sockets for both 30-pin and 72-pin SIMMs. If you have ever experienced the frustration of removing a SIMM module from a regular SIMM socket, you will be amazed at the ease of use of our unique SIMM socket. Pressing one button starts the fast BASIC test which automatically measures and displays the module size, Mode Type (including support for EDO), Access Time (speed), Cycle Time measurement and more. The BASIC test concludes with detailed structure information and you can terminate the test at this point if you wish, since BASIC test is sufficient for most of your testing needs.
If you decide to test the module more rigorously, do not terminate the test after BASIC test. EXTENSIVE test automatically follows with Voltage Cycling and Voltage Bounce tests which verify the module performance under varying voltage conditions. The March Up/Down algorithm detects interference among cells. Various tests like Relative Refresh and Relative Spikes provide detailed insight into the quality of the tested module. Our proprietary Chip-Heat mode automatically warms the chips for temperature related speed measurement at the end of EXTENSIVE test.
The AUTO-LOOP test provides the perfect burn-in means for your memory modules, as well as additional pattern testing.
In the SINGLE BIT test, SIMCHECK II identifies individual speed ratings and other related information for each bit.
SIMCHECK II incorporates advanced setup capabilities to satisfy the needs of even the most demanding engineers. Graphic setup allows you to control major timing parameters, and you can also change the test flow or edit patterns with ease.
Since R&D activities for a product like SIMCHECK II never end, one of our major design goals for SIMCHECK II was to create a STAND ALONE product with firmware which could be easily upgraded and expanded to protect your investment. This goal was achieved using modern FLASH EPROM technology and a PC Windows companion program, which allows you to download the firmware from our Web site on the Internet or from a distribution diskette. SIMCHECK II comes with a built-in serial interface for easy connection to the PC.
I recently bought an old SIMCheck II in the hopes that it'd be possible to clone for hobby use. I guess the inventor was very concerned about cloning when the device was new, because many of its ICs (even jellybean logic) have their silk screens sanded off. Further, there's an Altera CPLD present. I haven't checked yet, but would be really surprised if its security bit was not enabled. Perhaps that could be brute forced with something like the DuPAL, but that's an area I'm not familiar with.
For now here are a couple of board shots and an IC list of what's known on the 'processing board'.
Also, my unit has firmware 1.52. I'll try to dump and post that. The latest firmware is 1.55. If you have one of these units with newer firmware, it'd be much appreciated if you could dump and post it.
SIMCheck II Processing Board
SIMCheck II SIMM Board
Processing Board Semiconductor List
U1: TX486DLC/E-40GA CPU
U2/U3: Unknown
U4/U5/U6: Unknown
U7/U8/U9: Unknown
U10: Unknown
U11: ADM-692AM MicroprocessorSupervisory Circuits
U12: MIC29150 Voltage Regulator
U13: Unknown
U14/U15: 74ACT00PC Quad 2-Input NAND Gate
U16: EPM1032LC44-10 Altera Max 7000 programmable logic
U17: Unknown
U18: Unpopulated
U19/U20: AM29F010-90PC 1MBit CMOS 5V Flash Memory
U21/U22: W24257AK-15 32K×8 HIGH SPEED CMOS STATIC RAM
U23: MAX232CPE Serial Driver
U24: SCC2691AC1N24 UART
U25: D71059C-10 Interrupt Control Unit
U26: D71055C-10 CMOS Parallel Interface Unit
U27: D71054C-10 CMOS Programable Timer/Counter
U28: MC74HC174AN CMOS Hex D Flip-Flop with Common Clock and Reset
U29: MM74HC244N Octal 3-State Buffer
U30: Unknown
U31: 317T Voltage Regulator
U32: LM317 Voltage Regulator
U33: Unknown
U34: LX8385 Low Dropout Positive Regulator
U35: Unknown
U36: Unknown
U37: CD54HC377E High-Speed CMOS Logic Octal D-Type Flip-Flop With Data Enable
U38: 24C01A 1K Serial EEPROM
U39: Unpopulated
U40: 74ACQ244PC Quiet Series Octal Buffer/Line Driver with 3-STATE Outputs
And a little background about what the device is and does...
SIMCHECK II is the third generation of memory testers from the company that pioneered the RAMCHECK and SIMCHECK product lines. Based on a powerful, high-speed 32-bit 486 processor and utilizing state-of-the-art time delay circuitry, it significantly enhances the time proven testing capabilities that previous SIMCHECK users have come to depend on. Access time resolution of 1nS, cycle time measurement, graphic setup of timing parameters, true 3.3V testing and its unprecedented high speed testing are among these enhanced capabilities that up until now were not available in a portable memory tester.
A recent addition to our product line is the SIMCHECK II se, a lower cost version of the SIMCHECK II that uses many of the power features employed by SIMCHECK II. Please refer to Section 3.3 to view a comparison between SIMCHECK II and SIMCHECK II se.
With the move to SDRAM technology in the market place, we have released the SIMCHECK II PLUS and the SIMCHECK II se PLUS packages. These packages include the Sync DIMMCHECK 168 for testing SDRAM/EDO/FPM DIMMs. Please refer to Section 8.1 for further information on the Sync DIMMCHECK 168 Adapter.
SIMCHECK II tests all the standard 30/72-pin SIMM memory modules with sizes up to 4Gx40 and its modular design allows for virtually unlimited growth with optional adapters. Currently available adapters support SDRAM/EDO/FPM DIMMs, SO DIMMs, memory cards, and SOJ DRAM chips. If you have purchased a SIMCHECK II PLUS or a SIMCHECK II se PLUS, your tester can support the SDRAM/EDO/FPM DIMMs without an extra adapter.
Using our proprietary algorithms, SIMCHECK II runs a thorough test on the memory module, testing every memory cell. All chips (bits) are tested simultaneously to yield a faster test and to enable the instrument to detect errors that are caused by interference among the chips on the module. SIMCHECK II is not merely a go/no-go tester. In fact, it explicitly identifies the faulty bits within a defective module, and provides other important repair related information. While 100% accuracy in memory testing is technically impossible (See Appendix B), SIMCHECK II achieves a high degree of accuracy in detecting bad memory devices.
Since SIMCHECK II is fully automatic and extremely user friendly, anyone can use it with great ease. Its full graphics LCD display shows clear instructions and test results. It has Zero Insertion/Removal Sockets for both 30-pin and 72-pin SIMMs. If you have ever experienced the frustration of removing a SIMM module from a regular SIMM socket, you will be amazed at the ease of use of our unique SIMM socket. Pressing one button starts the fast BASIC test which automatically measures and displays the module size, Mode Type (including support for EDO), Access Time (speed), Cycle Time measurement and more. The BASIC test concludes with detailed structure information and you can terminate the test at this point if you wish, since BASIC test is sufficient for most of your testing needs.
If you decide to test the module more rigorously, do not terminate the test after BASIC test. EXTENSIVE test automatically follows with Voltage Cycling and Voltage Bounce tests which verify the module performance under varying voltage conditions. The March Up/Down algorithm detects interference among cells. Various tests like Relative Refresh and Relative Spikes provide detailed insight into the quality of the tested module. Our proprietary Chip-Heat mode automatically warms the chips for temperature related speed measurement at the end of EXTENSIVE test.
The AUTO-LOOP test provides the perfect burn-in means for your memory modules, as well as additional pattern testing.
In the SINGLE BIT test, SIMCHECK II identifies individual speed ratings and other related information for each bit.
SIMCHECK II incorporates advanced setup capabilities to satisfy the needs of even the most demanding engineers. Graphic setup allows you to control major timing parameters, and you can also change the test flow or edit patterns with ease.
Since R&D activities for a product like SIMCHECK II never end, one of our major design goals for SIMCHECK II was to create a STAND ALONE product with firmware which could be easily upgraded and expanded to protect your investment. This goal was achieved using modern FLASH EPROM technology and a PC Windows companion program, which allows you to download the firmware from our Web site on the Internet or from a distribution diskette. SIMCHECK II comes with a built-in serial interface for easy connection to the PC.
