The UP1500 is a motherboard built by Samsung and released in 2001, the last of the UP1x00 family. ¹⁾

• 800 MHz EV68AL with 2/4/8 MiB external L2 cache ²⁾, L2 cache bandwidth 8.5 GiB/s ³⁾
• AMD-761 Chipset, ALi M1535D+ south bridge
• 4x 184-pin DIMMs, supports 128 MiB to 4 GiB of ECC Registered PC2100 RAM (2.13 GiB/s ⁴⁾)
• 1x AGP (see Known issues)
• 3x 33 MHz 32-bit PCI slots
• DECchip 21143 Ethernet
• ALi M5451 Sound
• 2x Ultra DMA 33/66/100 IDE connectors, 2x USB ports, 2x serial ports, an ECP/EPP parallel port, and a floppy controller, all driven by the M1535D+, plus PS/2 keyboard and mouse ports ⁵⁾
• ATX form factor, 12 in x 9.6 in (30.48 cm x 24.38 cm) ⁶⁾
• Front panel connectors for the power button, reset button, power LED, hard disk activity LED, network receive LED, speaker, and keyboard lock ⁷⁾
• Configuration switchpack SW1: switches 1 and 2 select the firmware image (both on, the default, for the SRM console; both off for the fail-safe booter); switches 4, 5, and 6 set the system bus speed (off, off, on for 133 MHz, the default; all off for 100 MHz); switches 7 and 8 set the L2 cache size (on/off for 2 MiB, off/on for 4 MiB, off/off for 8 MiB, on/on to disable the cache) ⁸⁾

The UP1500 requires PC2100 ECC registered DDR SDRAM; unbuffered DIMMs do not work. ⁹⁾ Vendors tested modules from Viking ¹⁰⁾, Kingston, Kentron, and Corsair. ¹¹⁾ See UP1500 compatibility for DIMMs known to work. PC2700 ECC registered DIMMs have been reported to give better results under heavy use. ¹²⁾

The manual specifies a 300 W ATX supply, as for the UP1100, ¹³⁾ but a 400 W supply is recommended in practice. ¹⁴⁾

The original CPU fan is an 80x15 mm Nidec Beta SL (12 V, 0.09 A). The fan controller is reported to be sensitive, and many replacement fans do not work with it. ¹⁵⁾

The last SRM release for the UP1500 is 5.6-19. ¹⁶⁾ The final SRM revisions were made by Samsung to fix issues Hard Data found while testing the UP1500, and were distributed from Hard Data's FTP site. Samsung's development team was then reassigned to other projects. ¹⁷⁾ The UP1500's SRM has a newer BIOS emulator than the UP1000 and UP1100, and handles more video cards. ¹⁸⁾

A floppy image of the 5.6-19 update, srmupdt.5.6-19.img, is kept in the alphalinux/firmware repository. Written raw to a floppy, it gives a FAT floppy holding albasrm.rom and up1500fw.txt. After a power-up or reset, lfu is run at the SRM prompt, dva0 is given as the device and up1500fw.txt as the file list, and update at the UPD> prompt writes the console; the system must not lose power until it finishes. ¹⁹⁾

If an SRM update is interrupted, setting SW1 switches 1 and 2 off starts the fail-safe booter, which reloads the SRM console; the switches are returned to on afterwards. ²⁰⁾

Current kernels support the UP1500 with CONFIG_ALPHA_NAUTILUS or a generic kernel; it boots from SRM with aboot. ²¹⁾ The onboard Ethernet and sound work under Linux, as does an AGP Radeon 7500. ²²⁾ The onboard devices use the same drivers as on the UP1100: pata_ali for IDE, tulip for Ethernet, and snd-ali5451 for sound.

• AGP: the slot is keyed for 3.3 V signaling and runs at AGP 1x/2x, so cards that support only 1.5 V signaling (AGP 4x/8x only) do not fit, while universal cards do, ²³⁾ and it operates only as a PCI slot (see UP1000). Not all AGP cards that fit the slot work; see UP1500 compatibility.
• The IDE controller's DMA engine cannot perform 48-bit LBA transfers on ALi revisions before C5, so the pata_ali driver uses PIO for accesses beyond the first 128 GiB of a disk. ²⁴⁾
• I/O space needed for PCI counts against the amount of memory usable by the AMD-761. ²⁵⁾

API NetWorks did not distribute the UP1500, so resellers such as Hard Data bought it directly from Samsung. ²⁶⁾ Samsung stopped making Alpha boards in early 2002. ²⁷⁾