In marketing the Evo T20 Compaq described it as being "Legacy Free". What this
actually means is that it has no serial ports, no parallel port and no PS/2 ports for keyboard and mouse.
Also there is no standard PC BIOS. However the hardware components are standard. The basic specs are:
| Processor (&NB) | National Semiconductors Geode GX1, 300MHz | ||
| Memory | Depends on model. Variants are (Flash/RAM):
| ||
| Display (&SB) | National Semiconductors CS5530A. max. 4 MB VRAM. 1280x1024/16bpp | ||
| Ports | 4 x USB1.1 | ||
| Network | National Semiconductors DP83815 10/100 Mbit | ||
| Sound | Integrated in the CS5530A (Kahlua) - AC97 compatible | ||
| RTC | Dallas DS12885 (but NOT battery backed!) | ||
| Power | 5V 2amps(?) | ||
| Connections |
|
The circuit board does carry the words (c) WYSE TECHNOLOGY 2001. It's apparently a repackaged/rebadged Wyse 3235LE.
The Evo's I've seen are often sold without a power supply. This can be an irritant as the power
supply connector (DP-003-R) is not one that's readily available on the high street. However an on-line search
found me a UK supplier -
Toby Electronics - for those who want to fit the right connector to an existing power supply.
The Evo T20 requires a 5V supply. The standard Compaq power supply is rated at 4A (see picture right). Plugging my Evo T20 (16F/32M) into a mains power monitor shows an input drain of ~9W when the unit is supposedly off, rising to about 12W when the green LED is on and it's doing something.
As you can see from the label the connections on the plug are:
Pin 1&4 : +5V Pin 2&3 : NC Shield : GND
If you open the T20 you (may) have the opportunity to increase the amount of flash and RAM. To
remove the black cover place your thumbs in the two arcs in the black plastic on the rear of
the Evo and push gently upwards. Once the clips come clear you can slide the whole black cover
towards the rear and then remove it. This reveals the circuit board (see photo right) and you'll
find a SODIMM socket (at the top) and a Smart Media socket (at the bottom). On my Evo these
were unpopulated.
The SODIMM socket takes 144 pin PC133 SODIMM SDRAM memory. You'll find suitable memory advertised on ebay by people who've upgraded their laptops. A 128MB SODIMM can be picked up for £1 plus about the same again in postage charges. I believe the maximum memory supported is 256Mb. (So far I've only added 128Mb SODIMMs).
I've inserted an old 16MB Smart Media card that I have in the Smart Media socket and the system has recognised it. (With the original software loaded you can see this by going to Control Panel/System. It appears as Device 3). To date I haven't actually tried to program/use it. Unfortunately it looks like Smart Media cards of any reasonable size are not dirt cheap unlike Compact Flash cards.
Any comments? email me. Last update April 2009
