 Part of the firmware was held on an external 16 KB ROM cartridge also known as the "kludge" or "dongle", until the QL was redesigned to accommodate the necessary 48 KB of ROM internally, instead of the 32 KB initially specified.The QL also suffered from reliability problems of its Microdrives.These problems were later rectified, by Sinclair engineers, especially on Samsung produced models, as well as by aftermarket firms such as Adman Services and TF Services, to the point where several QL users report the Samsung Microdrives in particular working perfectly even after almost 17 years of service; but in any case much too late to redeem the negative image they had already created.