Programming FabISP Attiny44 with Arduino
Section 19 of the ATtiny24/44/84 datasheet, "Memory Programming", subsection 5, "Serial Programming", gives the minimum pulse width for ISP. Based on the values given (a minimum of 3 clock pulses for high and low each for a system clock >= 12MHz) the ISP clock must be no higher than 2MHz. As long as you can find a programming algorithm that respects that (and most do), you can use it to program the device.