This system got not more than a few hundred KB's of RAM. System configuration is stored on a EEPROM. The CPU is a 68k chip (yeah, same as Macintosh computers and several embedded devices of the era). This unity got the TMP68301AF-12 variant of that chip, manufactured by Toshiba.

The ROM complex is detachable, for reasons I deem unclear, since those chips are already seated on sockets. See below for more information on that detachable board.

This complex seems to be upgradeable (if you ever find that stuff.) Here we can find:

• IC20: P401A, matches the system ROM version (P401A60905A), so it's probably the main firmware;
• IC21: P402A, Google returns nothing useful, unknown ROM chip;
• IC24: CXK581000AP-10LL, or 131072-word × 8-bit High Speed CMOS Static RAM, which seems to provide our system with healthy 128 KB;
• IC25: idem, bringing the total amount of RAM in this module to 256 KB;
• IC26: OKI M6242B, an RTC clock chip;
• X2: 32.768 kHz crystal oscillator for the RTC chip;
• BAT: CR2354 battery, 3V, probaly of the /1GUF variant.

• The RTC battery is probably long dead and showing signs of oxidation on it's legs;
• There's was a bad and mysterious corrosion under the RTC oscillator, that I've already removed, after taking this photo;
• This same oscillator isn't operating reliably, sometimes it takes a while for the clock to start, well, clocking, and this component is probably the culprit; ## Chips under ROM/RTC card

Two proprietary parts are to be found here: - IC2: PQVI620890F - IC19: PQVI05JP031G, seems to be a EEPROM, simply referred as «ROM» in the parts list of TD816E service manual, and referred as «conference ROM» here(WebArchive).

I can't say (at this moment) what they are exactly, albeit I suspect they could be related to conference, tone generation and related functions.

Then we have: - IC3: MT8981D, didn't