Max Loader Custom Device Library

Additional device entries for the LG.DAT logic test library used by EE Tools Max Loader device programmers (TopMax, TopMax II, ChipMax, ChipMax2, UniMax, ProMax).

Max Loader ships with a library of TTL and CMOS logic test vectors, but its coverage of older bipolar memory, static RAM, and bus interface devices is thin. This repository adds entries for parts commonly found in arcade, pinball, and vintage computer hardware.

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Background

LG.DAT is a plain text file in the Max Loader installation directory, by default:

%ProgramFiles(x86)%\EETools

Each device is declared with a header line giving the part name and its DIP pin count, followed by one test vector per line. Within a vector, character position corresponds to physical pin number, counting from pin 1.

Character	Meaning
0 / 1	Programmer drives the pin low / high
L / H	Programmer expects to read a low / high level
Z	Programmer expects a high-impedance or undriven pin
X	Don't care, pin is not tested
C	Clock pulse
G	Ground
V	Vcc

Lines use CRLF endings. A vector must contain exactly as many characters as the pin count declared in its header. Note that G and V are not always on the last two pins: the 1489 places ground on pin 7, and parts such as the 7473 place Vcc mid-package.

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Files

File	Type	Size	Contents
LG.DAT.RAM	Complete library	54 KB	Static and bipolar RAM tests for the 82S09, 6116, and 93422
LG.DAT.KLOV	Add-on set	23 KB	16 memory and bus interface entries collected from the Arcade Museum (KLOV) community thread

LG.DAT.RAM is a complete replacement library. LG.DAT.KLOV is a set of additional entries intended to be appended to your existing library, not to replace it. See the installation notes for each below.

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Installation

Back up your original library before doing anything else.

Close Max Loader before modifying LG.DAT. The file is read at startup, so changes do not take effect until the software is restarted.

Installing LG.DAT.RAM

1. Navigate to the installation directory listed above.
2. Rename the existing LG.DAT to LG.DAT.Original.
3. Copy LG.DAT.RAM into that directory.
4. Rename it to LG.DAT.
5. Start Max Loader. The new devices appear in the device selection list.

To restore factory behaviour, rename LG.DAT.Original back to LG.DAT.

Installing LG.DAT.KLOV

These entries supplement the stock library rather than replacing it. Append the contents of LG.DAT.KLOV to the end of your existing LG.DAT using a text editor that preserves CRLF line endings. The combined file lands around 47 KB, comfortably inside the size limit described below.

Renaming LG.DAT.KLOV to LG.DAT outright will work, but you will lose the entire stock 7400-series library in the process.

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Device coverage

LG.DAT.RAM

Entry	Device	Package	Function	Vectors
.82S09	Signetics 82S09 / 82S19	28-pin DIP	64 x 9 bipolar RAM, inverting, open collector	519
.6116	6116 and compatibles	24-pin DIP	2K x 8 static RAM, three-state	519
.93422	AMD Am93422 and compatibles	22-pin DIP	256 x 4 bipolar RAM, noninverting, three-state	1065

Validation status. All three entries have been confirmed on hardware against both known-good and known-faulty devices. Good parts pass and faulty parts are correctly rejected.

Coverage. Each entry opens with a settle preamble and a set of memory-independent chip-disable checks, so a device that is unpowered or incorrectly seated fails within the first few vectors rather than partway through the array. A walking-bit section at a fixed address then verifies the data path one bit at a time. The main body writes the array and reads it back in a separate read-only pass, which is what gives genuine address decoder coverage.

Device compatibility notes.

• The 82S19 uses the same vector set as the 82S09. The two parts differ only in whether the outputs blank during a write cycle, and the outputs are marked don't-care during writes, so that difference is never exercised. Select 82S09 when testing an 82S19.
• The 93412 is the open-collector member of the 93422 family and shares its pinout. To convert, replace every H with Z inside the .93422 block and rename the entry. H appears nowhere except as an expected output level, so a find-and-replace scoped to that block is the entire change.

LG.DAT.KLOV

Entry	Device	Package	Function	Vectors
.8216	Intel 8216	16-pin DIP	4-bit bidirectional bus driver	12
.29701	AMD Am27901 (see naming note)	16-pin DIP	16 x 4 bipolar RAM, noninverting	64
.7489	7489	16-pin DIP	16 x 4 bipolar RAM, inverting, open collector	64
.74189	74189	16-pin DIP	16 x 4 bipolar RAM, inverting, three-state	64
.82S16	Signetics 82S16	16-pin DIP	256 x 1 bipolar RAM	1024
.25S09	AMD Am25S09	16-pin DIP	Quad 2-input high-speed register	4
.8212	Intel 8212	24-pin DIP	8-bit I/O port, three-state	13
.8T95	8T95	16-pin DIP	Hex buffer, noninverting, three-state	4
.8T96	8T96	16-pin DIP	Hex buffer, inverting, three-state	4
.8T97	8T97	16-pin DIP	Hex buffer, noninverting, three-state	11
.8T98	8T98	16-pin DIP	Hex buffer, inverting, three-state	6
.8T28	8T28	16-pin DIP	Quad bus transceiver, three-state	6
.8T38	8T38	16-pin DIP	Quad bus transceiver	6
.26LS31	AMD Am26LS31	16-pin DIP	Quad differential line driver, three-state	5
.26LS33	AMD Am26LS33	16-pin DIP	Quad differential line receiver, three-state	5
.1489	1489	14-pin DIP	Quad line receiver, ground on pin 7	2

Equivalent parts

Several of these entries cover more than one part number. Rather than duplicating vectors, either remember the equivalence or copy the block and rename it so the part appears under its own name in the device list.

16 x 4 bipolar RAM. The .7489 entry also tests the 74289, AMD Am27LS02, Intel P3101A, and 82S25. These are functionally identical for testing purposes.

Signetics 82S16. The .82S16 entry also tests the Fairchild 93321.

Motorola 68xx bus interface parts. Useful if you work on 6800-based systems:

Signetics	Motorola
8T28	MC6889
8T96	MC6886
8T97	MC6887
8T98	MC6888

Naming note on .29701

The originating forum post describes this device as the AM27901, but the entry is named .29701. One of the two has transposed digits, and the source material does not resolve which. The vectors themselves are unambiguous: writing a 0 reads back L and writing a 1 reads back H, confirming non-inverting outputs as described. The entry name has been left as published. Verify the part number on your device before relying on it.

For reference, the TTL part with the same organization and non-inverting outputs is the 74219.

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Technical notes

Two constraints are worth knowing about before you write your own entries. Neither is documented by the vendor, and both cost real debugging time to find.

Max Loader has a 64 KB library ceiling

ml.exe parses LG.DAT into a fixed buffer. Exceeding roughly 65,536 bytes produces a null-pointer dereference rather than a graceful error:

Access violation at address 00526263 in module 'ml.exe'. Read of address 00000000.

The failure occurs at load time, not at test time, and the offending entry is not identified. If you see this dialog after editing the library, check the file size first. This is why device families here are distributed as separate libraries rather than as one combined file.

RAM entries require guarded writes

The programmer applies each vector by updating its pin drivers, with no guarantee about the relative order in which individual pins settle. If the address bus changes state while /WE is asserted, the device writes to whatever intermediate addresses the bus passes through, silently corrupting locations that were never targeted.

Every write in the LG.DAT.RAM entries is therefore a three-vector sequence:

0000000001111G0XXXXXXXXX000V    address and data set, /WE high
0000000001110G0XXXXXXXXX000V    /WE pulsed low, address already stable
0000000001111G0XXXXXXXXX000V    /WE returned high before the address moves

The address is only ever allowed to change while /WE is high. A single unguarded write is enough to fail a test, including the very first vector of an entry, where the device may still be settling after power is applied.

With this in place, a write-all-then-read-all structure is safe, and the readback pass provides address decoder coverage that a simple write-then-verify-immediately pattern cannot.

The older LG.DAT.KLOV RAM entries take the alternative approach of writing and verifying each address immediately, which tolerates the glitch but cannot detect address aliasing. Both approaches are valid; they trade coverage against vector count.

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Validation

All entries in this repository have been checked programmatically for structural correctness: every vector matches its declared pin count, uses only valid characters, and places G and V on consistent pins throughout its entry.

Structural validity is not the same as functional correctness, so the LG.DAT.RAM entries have additionally been validated on hardware against both known-good and known-faulty devices.

Testing against a failing device matters as much as testing against a working one. A vector set that is too permissive passes every part put in front of it, and a vector set containing an error fails every part regardless of condition. Neither fault is visible if you only ever test known-good silicon.

The LG.DAT.KLOV entries are reproduced as published and have not been independently re-verified here.

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Credits

The LG.DAT.KLOV entries were contributed by channelmanic in the Arcade Museum forum thread Adding chips to Max Loader, along with the accompanying part equivalence notes reproduced above.

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Disclaimer

These entries are provided as-is. Verify any pinout against the manufacturer datasheet before use, and keep a backup of your original LG.DAT. Testing a device with an incorrect vector set can damage it.

Contributing

Additional device entries are welcome. Please include the manufacturer and part number, the package and pin count, a note on whether the outputs are three-state or open collector, and confirmation that the entry has been validated against a known-good device.